Index: trunk/core/admin_templates/js/catalog.js
===================================================================
diff -u -r5078 -r5084
--- trunk/core/admin_templates/js/catalog.js	(.../catalog.js)	(revision 5078)
+++ trunk/core/admin_templates/js/catalog.js	(.../catalog.js)	(revision 5084)
@@ -15,7 +15,7 @@
 
 Catalog.prototype.Init = function () {
 	var $prefix = this.queryTabRegistry('prefix', this.ActivePrefix, 'prefix');
-	if ($prefix !== this.ActivePrefix && this.TabRegistry.length > 0) {
+	if ($prefix !== this.ActivePrefix && this.TabRegistry.length > 1) {
 		// ActivePrefix not set or has non-existing prefix value
 		this.ActivePrefix = this.TabRegistry[1]['prefix'];
 	}
@@ -128,6 +128,11 @@
 
 
 Catalog.prototype.switchTab = function($prefix) {
+	if (this.queryTabRegistry('prefix', this.ActivePrefix, 'prefix') != this.ActivePrefix) {
+		// active prefix is not registred -> cookie left, but not modules installed/enabled at the moment
+		return false;
+	}
+	
 	if (!isset($prefix)) $prefix = this.ActivePrefix;
 
 	if (this.BusyRequest[$prefix]) {