Index: extensions/AMenuManager/amm_install.class.inc.php
===================================================================
--- extensions/AMenuManager/amm_install.class.inc.php	(revision 8962)
+++ extensions/AMenuManager/amm_install.class.inc.php	(revision 8971)
@@ -310,5 +310,5 @@
       pwg_query("UPDATE ".CONFIG_TABLE." SET value = '' WHERE param='blk_menubar';");
 
-      if($updateMenu)
+      if($updateMenu and $conf['blk_menubar']!='')
       {
         $tmp=unserialize($conf['blk_menubar']);
@@ -325,5 +325,6 @@
     private function restoreMenuConfig()
     {
-      pwg_query("UPDATE ".CONFIG_TABLE." SET value = '".pwg_db_real_escape_string($this->config['amm_old_blk_menubar'])."' WHERE param='blk_menubar';");
+      if($this->config['amm_old_blk_menubar']!='')
+        pwg_query("UPDATE ".CONFIG_TABLE." SET value = '".pwg_db_real_escape_string($this->config['amm_old_blk_menubar'])."' WHERE param='blk_menubar';");
     }