diff --git a/coffee/db_interface.coffee b/coffee/db_interface.coffee
index f7b5774..fbed5e3 100644
--- a/coffee/db_interface.coffee
+++ b/coffee/db_interface.coffee
@@ -22,7 +22,7 @@ DB Interface
 'use strict'
 ### Grab all required modules ###
 redis = require 'redis'
-crypto = require 'crypto'
+crypto = require 'crypto' # TODO change to Google's "crypto-js""
 log = require './logging'
 crypto_key = null
 db = null
@@ -129,7 +129,8 @@ via the provided function and returns the results to the callback(err, obj) func
 @param {function} fSingle a function to retrieve a single data element per set entry
 @param {function} cb the callback(err, obj) function that receives all the retrieved data or an error
 ###
-getSetRecords = (set, funcSingle, cb) ->
+getSetRecords = (set, fSingle, cb) ->
+  log.print 'DB', 'Fetching set records: ' + set
   db?.smembers set, (err, arrReply) ->
     if err
       err.addInfo = 'fetching ' + set
@@ -146,12 +147,15 @@ getSetRecords = (set, funcSingle, cb) ->
       , 2000
       fCallback = (prop) ->
         (err, data) ->
+          --semaphore
           if err
             err.addInfo = 'fetching single element: ' + prop
             log.error 'DB', err
-          else 
+          else if not data
+            log.error 'DB', new Error 'Empty key in DB: ' + prop
+          else
             objReplies[prop] = data
-            if --semaphore == 0
+            if semaphore == 0
               cb null, objReplies
       fSingle reply, fCallback(reply) for reply in arrReply
 
@@ -168,6 +172,7 @@ Store a string representation of an action module in the DB.
 ###
 # FIXME can the data be an object?
 exports.storeActionModule = (id, data) ->
+  log.print 'DB', 'storeActionModule: ' + id
   db?.sadd 'action-modules', id, replyHandler 'storing action module key ' + id
   db?.set 'action-module:' + id, data, replyHandler 'storing action module ' + id
 
@@ -179,6 +184,7 @@ Query the DB for an action module and pass it to the callback(err, obj) function
 @param {function} cb
 ###
 exports.getActionModule = (id, cb) ->
+  log.print 'DB', 'getActionModule: ' + id
   db?.get 'action-module:' + id, cb
 
 ###
@@ -199,6 +205,7 @@ Store a string representation of the authentication parameters for an action mod
 @param {String} data
 ###
 exports.storeActionAuth = (userId, moduleId, data) ->
+  log.print 'DB', 'storeActionAuth: ' + userId + ':' + moduleId
   db?.set 'action-auth:' + userId + ':' + moduleId, encrypt(data),
   replyHandler 'storing action auth ' + userId + ':' + moduleId
 
@@ -212,6 +219,7 @@ and pass it to the callback(err, obj) function.
 @param {function} cb
 ###
 exports.getActionAuth = (userId, moduleId, cb) ->
+  log.print 'DB', 'getActionAuth: ' + userId + ':' + moduleId
   db?.get 'action-auth:' + userId + ':' + moduleId, (err, data) ->
     cb err, decrypt data
 
@@ -228,6 +236,7 @@ Store a string representation of an event module in the DB.
 @param {String} data
 ###
 exports.storeEventModule = (id, data) ->
+  log.print 'DB', 'storeEventModule: ' + id
   db?.sadd 'event-modules', id, replyHandler 'storing event module key ' + id
   db?.set 'event-module:' + id, data, replyHandler 'storing event module ' + id
 
@@ -239,6 +248,7 @@ Query the DB for an event module and pass it to the callback(err, obj) function.
 @param {function} cb
 ###
 exports.getEventModule = (id, cb) ->
+  log.print 'DB', 'getEventModule: ' + id
   db?.get 'event_module:' + id, cb
 
 ###
@@ -258,6 +268,7 @@ Store a string representation of he authentication parameters for an event modul
 @param {String} data
 ###
 exports.storeEventAuth = (userId, moduleId, data) ->
+  log.print 'DB', 'storeEventAuth: ' + userId + ':' + moduleId
   db?.set 'event-auth:' + userId + ':' + moduleId, encrypt(data),
   replyHandler 'storing event auth ' + userId + ':' + moduleId
   
@@ -269,6 +280,7 @@ Query the DB for an action module authentication token, associated with a user.
 @param {function} cb
 ###
 exports.getEventAuth = (userId, moduleId, cb) ->
+  log.print 'DB', 'getEventAuth: ' + userId + ':' + moduleId
   db?.get 'event-auth:' + userId + ':' + moduleId, (err, data) ->
     cb err, decrypt data
 
@@ -285,6 +297,7 @@ Store a string representation of a rule in the DB.
 @param {String} data
 ###
 exports.storeRule = (id, data) ->
+  log.print 'DB', 'storeRule: ' + id
   db?.sadd 'rules', id, replyHandler 'storing rule key ' + id
   db?.set 'rule:' + id, data, replyHandler 'storing rule ' + id
 
@@ -296,6 +309,7 @@ Query the DB for a rule and pass it to the callback(err, obj) function.
 @param {function} cb
 ###
 exports.getRule = (id, cb) ->
+  log.print 'DB', 'getRule: ' + id
   db?.get 'rule:' + id, cb
 
 ###
@@ -305,6 +319,7 @@ Fetch all rules from the database and pass them to the callback function.
 @param {function} cb
 ###
 exports.getRules = (cb) ->
+  log.print 'DB', 'Fetching all Rules'
   getSetRecords 'rules', exports.getRule, cb
 
 ###
@@ -314,6 +329,7 @@ Store a user object (needs to be a flat structure).
 @param {Object} objUser
 ###
 exports.storeUser = (objUser) ->
+  log.print 'DB', 'storeUser: ' + objUser.username
   if objUser and objUser.username and objUser.password
     db?.sadd 'users', objUser.username, replyHandler 'storing user key ' + objUser.username
     objUser.password = encrypt objUser.password
@@ -329,6 +345,7 @@ Associate a role with a user.
 @param {String} role
 ###
 exports.storeUserRole = (username, role) ->
+  log.print 'DB', 'storeUserRole: ' + username + ':' + role
   db?.sadd 'user-roles:' + username, role, replyHandler 'adding role ' + role + ' to user ' + username
   db?.sadd 'role-users:' + role, username, replyHandler 'adding user ' + username + ' to role ' + role
 
@@ -339,6 +356,7 @@ Fetch all roles of a user and pass them to the callback(err, obj)
 @param {String} username
 ###
 exports.getUserRoles = (username) ->
+  log.print 'DB', 'getUserRole: ' + username
   db?.get 'user-roles:' + username, cb
   
 ###
@@ -348,6 +366,7 @@ Fetch all users of a role and pass them to the callback(err, obj)
 @param {String} role
 ###
 exports.getRoleUsers = (role) ->
+  log.print 'DB', 'getRoleUsers: ' + role
   db?.get 'role-users:' + role, cb
 
 ###
@@ -360,18 +379,22 @@ Checks the credentials and on success returns the user object to the callback(er
 ###
 # TODO verify and test whole function
 exports.loginUser = (username, password, cb) ->
+  log.print 'DB', 'User "' + username + '" tries to log in'
   fCheck = (pw) ->
     (err, obj) ->
       if err 
-        cb? err
-      else if obj and obj.password 
-        if encrypt(obj.password) == pw
-          cb? null, obj
-        else cb? new Error 'Wrong credentials!'
+        cb err
+      else if obj and obj.password
+        if encrypt(pw) == obj.password
+          log.print 'DB', 'User "' + obj.username + '" logged in!' 
+          cb null, obj
+        else
+          cb new Error 'Wrong credentials!'
       else
-        cb? new Error 'Empty arguments!'
-  db?.get 'user:' + username, fCheck password
+        cb new Error 'Empty arguments!'
+  db?.hgetall 'user:' + username, fCheck password
 
+# TODO implement functions required for user sessions and the rule activation
 
 ###
 Shuts down the db link.
diff --git a/js-coffee/db_interface.js b/js-coffee/db_interface.js
index d25fcb0..77a9afc 100644
--- a/js-coffee/db_interface.js
+++ b/js-coffee/db_interface.js
@@ -173,7 +173,8 @@ DB Interface
   */
 
 
-  getSetRecords = function(set, funcSingle, cb) {
+  getSetRecords = function(set, fSingle, cb) {
+    log.print('DB', 'Fetching set records: ' + set);
     return db != null ? db.smembers(set, function(err, arrReply) {
       var fCallback, objReplies, reply, semaphore, _i, _len, _results;
       if (err) {
@@ -191,12 +192,15 @@ DB Interface
         }, 2000);
         fCallback = function(prop) {
           return function(err, data) {
+            --semaphore;
             if (err) {
               err.addInfo = 'fetching single element: ' + prop;
               return log.error('DB', err);
+            } else if (!data) {
+              return log.error('DB', new Error('Empty key in DB: ' + prop));
             } else {
               objReplies[prop] = data;
-              if (--semaphore === 0) {
+              if (semaphore === 0) {
                 return cb(null, objReplies);
               }
             }
@@ -227,6 +231,7 @@ DB Interface
 
 
   exports.storeActionModule = function(id, data) {
+    log.print('DB', 'storeActionModule: ' + id);
     if (db != null) {
       db.sadd('action-modules', id, replyHandler('storing action module key ' + id));
     }
@@ -243,6 +248,7 @@ DB Interface
 
 
   exports.getActionModule = function(id, cb) {
+    log.print('DB', 'getActionModule: ' + id);
     return db != null ? db.get('action-module:' + id, cb) : void 0;
   };
 
@@ -269,6 +275,7 @@ DB Interface
 
 
   exports.storeActionAuth = function(userId, moduleId, data) {
+    log.print('DB', 'storeActionAuth: ' + userId + ':' + moduleId);
     return db != null ? db.set('action-auth:' + userId + ':' + moduleId, encrypt(data), replyHandler('storing action auth ' + userId + ':' + moduleId)) : void 0;
   };
 
@@ -284,6 +291,7 @@ DB Interface
 
 
   exports.getActionAuth = function(userId, moduleId, cb) {
+    log.print('DB', 'getActionAuth: ' + userId + ':' + moduleId);
     return db != null ? db.get('action-auth:' + userId + ':' + moduleId, function(err, data) {
       return cb(err, decrypt(data));
     }) : void 0;
@@ -304,6 +312,7 @@ DB Interface
 
 
   exports.storeEventModule = function(id, data) {
+    log.print('DB', 'storeEventModule: ' + id);
     if (db != null) {
       db.sadd('event-modules', id, replyHandler('storing event module key ' + id));
     }
@@ -320,6 +329,7 @@ DB Interface
 
 
   exports.getEventModule = function(id, cb) {
+    log.print('DB', 'getEventModule: ' + id);
     return db != null ? db.get('event_module:' + id, cb) : void 0;
   };
 
@@ -345,6 +355,7 @@ DB Interface
 
 
   exports.storeEventAuth = function(userId, moduleId, data) {
+    log.print('DB', 'storeEventAuth: ' + userId + ':' + moduleId);
     return db != null ? db.set('event-auth:' + userId + ':' + moduleId, encrypt(data), replyHandler('storing event auth ' + userId + ':' + moduleId)) : void 0;
   };
 
@@ -358,6 +369,7 @@ DB Interface
 
 
   exports.getEventAuth = function(userId, moduleId, cb) {
+    log.print('DB', 'getEventAuth: ' + userId + ':' + moduleId);
     return db != null ? db.get('event-auth:' + userId + ':' + moduleId, function(err, data) {
       return cb(err, decrypt(data));
     }) : void 0;
@@ -378,6 +390,7 @@ DB Interface
 
 
   exports.storeRule = function(id, data) {
+    log.print('DB', 'storeRule: ' + id);
     if (db != null) {
       db.sadd('rules', id, replyHandler('storing rule key ' + id));
     }
@@ -394,6 +407,7 @@ DB Interface
 
 
   exports.getRule = function(id, cb) {
+    log.print('DB', 'getRule: ' + id);
     return db != null ? db.get('rule:' + id, cb) : void 0;
   };
 
@@ -406,6 +420,7 @@ DB Interface
 
 
   exports.getRules = function(cb) {
+    log.print('DB', 'Fetching all Rules');
     return getSetRecords('rules', exports.getRule, cb);
   };
 
@@ -418,6 +433,7 @@ DB Interface
 
 
   exports.storeUser = function(objUser) {
+    log.print('DB', 'storeUser: ' + objUser.username);
     if (objUser && objUser.username && objUser.password) {
       if (db != null) {
         db.sadd('users', objUser.username, replyHandler('storing user key ' + objUser.username));
@@ -439,6 +455,7 @@ DB Interface
 
 
   exports.storeUserRole = function(username, role) {
+    log.print('DB', 'storeUserRole: ' + username + ':' + role);
     if (db != null) {
       db.sadd('user-roles:' + username, role, replyHandler('adding role ' + role + ' to user ' + username));
     }
@@ -454,6 +471,7 @@ DB Interface
 
 
   exports.getUserRoles = function(username) {
+    log.print('DB', 'getUserRole: ' + username);
     return db != null ? db.get('user-roles:' + username, cb) : void 0;
   };
 
@@ -466,6 +484,7 @@ DB Interface
 
 
   exports.getRoleUsers = function(role) {
+    log.print('DB', 'getRoleUsers: ' + role);
     return db != null ? db.get('role-users:' + role, cb) : void 0;
   };
 
@@ -481,22 +500,24 @@ DB Interface
 
   exports.loginUser = function(username, password, cb) {
     var fCheck;
+    log.print('DB', 'User "' + username + '" tries to log in');
     fCheck = function(pw) {
       return function(err, obj) {
         if (err) {
-          return typeof cb === "function" ? cb(err) : void 0;
+          return cb(err);
         } else if (obj && obj.password) {
-          if (encrypt(obj.password) === pw) {
-            return typeof cb === "function" ? cb(null, obj) : void 0;
+          if (encrypt(pw) === obj.password) {
+            log.print('DB', 'User "' + obj.username + '" logged in!');
+            return cb(null, obj);
           } else {
-            return typeof cb === "function" ? cb(new Error('Wrong credentials!')) : void 0;
+            return cb(new Error('Wrong credentials!'));
           }
         } else {
-          return typeof cb === "function" ? cb(new Error('Empty arguments!')) : void 0;
+          return cb(new Error('Empty arguments!'));
         }
       };
     };
-    return db != null ? db.get('user:' + username, fCheck(password)) : void 0;
+    return db != null ? db.hgetall('user:' + username, fCheck(password)) : void 0;
   };
 
   /*
diff --git a/js-coffee/engine.js b/js-coffee/engine.js
index 68664e0..d79cecc 100644
--- a/js-coffee/engine.js
+++ b/js-coffee/engine.js
@@ -63,7 +63,10 @@ exports.addDBLinkAndLoadActionsAndRules = function(db_link) {
 
 function loadRulesFromDB() {
   if(db) db.getRules(function(err, obj) {
-    for(var el in obj) exports.addRule(JSON.parse(obj[el]));
+    for(var el in obj){
+      if(obj[el]) exports.addRule(JSON.parse(obj[el]));
+    }
+      
   });
 }
 
@@ -82,6 +85,8 @@ exports.loadActionModule = function(name, objModule) {
  */
 exports.addRule = function(objRule) {
   //TODO validate rule
+  log.print('EN', 'Loading Rule');
+  log.print('EN', objRule);
   log.print('EN', 'Loading Rule: ' + objRule.id);
   if(listRules[objRule.id]) log.print('EN', 'Replacing rule: ' + objRule.id);
   listRules[objRule.id] = objRule;
diff --git a/js-coffee/logging.js b/js-coffee/logging.js
index d4ee683..336d081 100644
--- a/js-coffee/logging.js
+++ b/js-coffee/logging.js
@@ -55,7 +55,10 @@ exports.print = function(module, msg) {
  */
 function printError(module, err, isSevere) {
   var ts = (new Date()).toISOString() + ' | ', ai = '';
-  if(!err) err = new Error('Unexpected error');
+  if(!err) {
+    err = new Error('Unexpected error');
+    isSevere = true;
+  }
   if(typeof err === 'string') err = new Error(err);
     // if(module) flush(true, ts + module + ' | ERROR AND BAD HANDLING: ' + err + '\n' + e.stack);
     // else flush(true, ts + '!N/A! | ERROR, BAD HANDLING AND NO MODULE NAME: ' + err + '\n' + e.stack);
diff --git a/js-coffee/user_handler.js b/js-coffee/user_handler.js
index 7511ed8..0eed5b8 100644
--- a/js-coffee/user_handler.js
+++ b/js-coffee/user_handler.js
@@ -9,8 +9,9 @@ exports = module.exports = function(args) {
   log(args);
   db(args);
   var users = JSON.parse(require('fs').readFileSync(path.resolve(__dirname, '..', 'config', 'users.json')));
-  for(var name in users) {
-    db.storeUser(users[name]);
+  for(var i = 0; i < users.length; i++) {
+    log.print('UH', 'Found user ' + users[i].username + ' in user file, storing him in the DB');
+    db.storeUser(users[i]);
   }
  
   return module.exports;
@@ -42,13 +43,20 @@ exports.handleLogin = function(req, resp) {
     if(!req.session || !req.session.user) {
       var obj = qs.parse(body);
       db.loginUser(obj.username, obj.password, function(err, obj) {
-        if(!err) req.session.user = obj;
-        if(req.session.user) {
-          resp.write('Welcome ' + req.session.user.name + '!');
-        } else {
+        if(err) {
+          log.error('UH', err);
           resp.writeHead(401, { "Content-Type": "text/plain" });
           resp.write('Login failed!');
         }
+        else {
+          req.session.user = obj;
+          if(req.session.user) {
+            resp.write('Welcome ' + req.session.user.name + '!');
+          } else {
+            resp.writeHead(401, { "Content-Type": "text/plain" });
+            resp.write('Login failed!');
+          }
+        }
         resp.end();
       });
     }
diff --git a/js/engine.js b/js/engine.js
index 68664e0..79916a9 100644
--- a/js/engine.js
+++ b/js/engine.js
@@ -30,13 +30,14 @@ exports = module.exports = function(args) {
  * @param {String} crypto_key the key to be used for encryption on the db, max legnth 256
  */
 exports.addDBLinkAndLoadActionsAndRules = function(db_link) {
+  //TODO only load rules on beginning, if rules require certain actions, load them in order to allow fast firing
+  // if rules are set inactive, remove the action module from the memory
   db = db_link;
   if(ml && db) db.getActionModules(function(err, obj) {
     if(err) log.error('EN', 'retrieving Action Modules from DB!');
     else {
       if(!obj) {
         log.print('EN', 'No Action Modules found in DB!');
-        loadRulesFromDB();
       } else {
         var m;
         for(var el in obj) {
@@ -54,23 +55,22 @@ exports.addDBLinkAndLoadActionsAndRules = function(db_link) {
             log.error('EN', e);
           }
         }
-        loadRulesFromDB();
       }
     }
+    if(db) db.getRules(function(err, obj) {
+      for(var el in obj) exports.addRule(JSON.parse(obj[el]));
+    });
   });
   else log.severe('EN', new Error('Module Loader or DB not defined!'));
 };
 
-function loadRulesFromDB() {
-  if(db) db.getRules(function(err, obj) {
-    for(var el in obj) exports.addRule(JSON.parse(obj[el]));
-  });
-}
 
 /**
  * Insert an action module into the list of available interfaces.
  * @param {Object} objModule the action module object
  */
+//TODO action modules should be loaded once a user activates a rule with the respective
+// action, if the user deletes the rule it has to be garrbage collected from the engine's list 
 exports.loadActionModule = function(name, objModule) {
   log.print('EN', 'Action module "' + name + '" loaded');
   listActionModules[name] = objModule;
@@ -82,6 +82,7 @@ exports.loadActionModule = function(name, objModule) {
  */
 exports.addRule = function(objRule) {
   //TODO validate rule
+  log.print('EN', 'Loading Rule');
   log.print('EN', 'Loading Rule: ' + objRule.id);
   if(listRules[objRule.id]) log.print('EN', 'Replacing rule: ' + objRule.id);
   listRules[objRule.id] = objRule;
diff --git a/js/eventpoller.js b/js/eventpoller.js
index 7198bc1..0be62b9 100644
--- a/js/eventpoller.js
+++ b/js/eventpoller.js
@@ -121,6 +121,7 @@ function checkRemotes() {
        * define and immediately call anonymous function with param prop.
        * This places the value of prop into the context of the callback
        * and thus doesn't change when the for loop keeps iterating over listPoll
+       * TODO add this example to the documentation and elaborate
        */
         (function(p) {
           return function(err, obj) {
diff --git a/js/logging.js b/js/logging.js
index d4ee683..abed35d 100644
--- a/js/logging.js
+++ b/js/logging.js
@@ -55,18 +55,21 @@ exports.print = function(module, msg) {
  */
 function printError(module, err, isSevere) {
   var ts = (new Date()).toISOString() + ' | ', ai = '';
-  if(!err) err = new Error('Unexpected error');
+  if(!err) {
+    err = new Error('Unexpected error');
+    isSevere = true;
+  }
   if(typeof err === 'string') err = new Error(err);
     // if(module) flush(true, ts + module + ' | ERROR AND BAD HANDLING: ' + err + '\n' + e.stack);
     // else flush(true, ts + '!N/A! | ERROR, BAD HANDLING AND NO MODULE NAME: ' + err + '\n' + e.stack);
   // } else if(err) {
-    if(err.addInfo) ai = ' (' + err.addInfo + ')';
-    if(!err.message) err.message = 'UNKNOWN REASON!\n' + err.stack;
-    if(module) {
-      var msg = ts + module + ' | ERROR'+ai+': ' + err.message;
-      if(isSevere) msg += '\n' + err.stack;
-      flush(true, msg);
-    } else flush(true, ts + '!N/A! | ERROR AND NO MODULE NAME'+ai+': ' + err.message + '\n' + err.stack);
+  if(err.addInfo) ai = ' (' + err.addInfo + ')';
+  if(!err.message) err.message = 'UNKNOWN REASON!\n' + err.stack;
+  if(module) {
+    var msg = ts + module + ' | ERROR'+ai+': ' + err.message;
+    if(isSevere) msg += '\n' + err.stack;
+    flush(true, msg);
+  } else flush(true, ts + '!N/A! | ERROR AND NO MODULE NAME'+ai+': ' + err.message + '\n' + err.stack);
   // } else {
     // var e = new Error('Unexpected error');
     // flush(true, e.message + ': \n' + e.stack);
diff --git a/package.json b/package.json
index 5c1a0d2..0c5cac3 100644
--- a/package.json
+++ b/package.json
@@ -21,8 +21,6 @@
     "dependencies": {
     	"glob" :"3.2.7",
     	"docco": "0.6.2",
-      "groc": "0.6.1",
-      "diff": "1.0.5",
       "socket.io": "0.9.16",
       "contextify": "0.1.6"
     }