diff --git a/home/index.php b/home/index.php
index b2b0813362..104dd19188 100755
--- a/home/index.php
+++ b/home/index.php
@@ -78,13 +78,16 @@
 	** Display the mainscreen message
 	*/
 	$GLOBALS['egw']->translation->add_app('mainscreen');
-	if(translation::translate('mainscreen_message',false,'') == 'mainscreen_message')
+	$greeting = translation::translate('mainscreen_message',false,'');
+
+	if($greeting == 'mainscreen_message'||empty($greeting))
 	{
 		translation::add_app('mainscreen','en');    // trying the en one
+		$greeting = translation::translate('mainscreen_message',false,'');
 	}
-	if(translation::translate('mainscreen_message',false,'') != 'mainscreen_message')
+	if(!($greeting == 'mainscreen_message'||empty($greeting)))
 	{
-		echo '<div style="text-align: center;">' . lang('mainscreen_message') . "</div>\n";
+		echo '<div style="text-align: center;">' . $greeting . "</div>\n";
 	}
 
 	/*
diff --git a/login.php b/login.php
index 97a7aad5e2..eeb32e670e 100755
--- a/login.php
+++ b/login.php
@@ -393,18 +393,19 @@ else
 			$GLOBALS['egw_info']['user']['preferences']['common']['lang'] = $lang;
 		}
 		#print 'LANG:' . $GLOBALS['egw_info']['user']['preferences']['common']['lang'] . '<br>';
-
 		translation::init();	// this will set the language according to the (new) set prefs
 		translation::add_app('login');
 		translation::add_app('loginscreen');
-		if(translation::translate('loginscreen_message',false,'') == 'loginscreen_message')
+		$GLOBALS['loginscreenmessage'] = translation::translate('loginscreen_message',false,'');
+		if($GLOBALS['loginscreenmessage'] == 'loginscreen_message' || empty($GLOBALS['loginscreenmessage']))
 		{
-		   translation::add_app('loginscreen','en');	// trying the en one
+			translation::add_app('loginscreen','en');	// trying the en one
+			$GLOBALS['loginscreenmessage'] = translation::translate('loginscreen_message',false,'');
 		}
-		if(translation::translate('loginscreen_message',false,'') != 'loginscreen_message')
+		if($GLOBALS['loginscreenmessage'] == 'loginscreen_message' || empty($GLOBALS['loginscreenmessage']))
 		{
-		   // for now store login message in globals so it is available for the login.inc.php
-		   $GLOBALS['loginscreenmessage']=stripslashes(lang('loginscreen_message'));
+		   // remove the global var since the lang loginscreen message and its fallback (en) is empty or not set
+		   unset($GLOBALS['loginscreenmessage']);
 		}
 	}
 
diff --git a/phpgwapi/inc/class.translation.inc.php b/phpgwapi/inc/class.translation.inc.php
index 01c7cabdcb..e1a0a6e1f3 100644
--- a/phpgwapi/inc/class.translation.inc.php
+++ b/phpgwapi/inc/class.translation.inc.php
@@ -935,7 +935,17 @@ class translation
 		),__LINE__,__FILE__);
 
 		// invalidate the cache
-		egw_cache::unsetCache(in_array($app,self::$instance_specific_translations) ? egw_cache::INSTANCE : egw_cache::TREE,__CLASS__,$app.':'.$lang);
+		if(!in_array($app,self::$instance_specific_translations))
+		{
+			egw_cache::unsetCache(egw_cache::TREE,__CLASS__,$app.':'.$lang);
+		}
+		else
+		{
+			foreach((array)self::get_installed_langs() as $key => $name)
+			{
+				egw_cache::unsetCache(egw_cache::INSTANCE,__CLASS__,$app.':'.$key);
+			}
+		}
 	}
 
 	/**