Index: typo3/sysext/cms/tslib/media/scripts/gmenu_layers.php
===================================================================
--- typo3/sysext/cms/tslib/media/scripts/gmenu_layers.php	(revision 8942)
+++ typo3/sysext/cms/tslib/media/scripts/gmenu_layers.php	(working copy)
@@ -114,7 +114,7 @@
 	 * @return	void
 	 */
 	function extProc_init()	{
-		$this->WMid = trim($this->mconf['layer_menu_id'])?trim($this->mconf['layer_menu_id']).'x':substr(md5(microtime()),0,6);	// NO '_' (underscore) in the ID!!! NN4 breaks!
+		$this->WMid = trim($this->mconf['layer_menu_id']) ? trim($this->mconf['layer_menu_id']) . 'x' : substr(md5('gl' . serialize($this->result)), 0, 6);
 
 		$GLOBALS['TSFE']->applicationData['GMENU_LAYERS']['WMid'][]=$this->WMid;
 		$this->WMtempStore = $GLOBALS['TSFE']->applicationData['GMENU_LAYERS']['WMid'];
Index: typo3/sysext/cms/tslib/media/scripts/tmenu_layers.php
===================================================================
--- typo3/sysext/cms/tslib/media/scripts/tmenu_layers.php	(revision 8942)
+++ typo3/sysext/cms/tslib/media/scripts/tmenu_layers.php	(working copy)
@@ -114,7 +114,7 @@
 	 * @return	void
 	 */
 	function extProc_init()	{
-		$this->WMid = trim($this->mconf['layer_menu_id'])?trim($this->mconf['layer_menu_id']).'x':substr(md5(microtime()),0,6);	// NO '_' (underscore) in the ID!!! NN4 breaks!
+		$this->WMid = trim($this->mconf['layer_menu_id']) ? trim($this->mconf['layer_menu_id']) . 'x' : substr(md5('gl' . serialize($this->result)), 0, 6);
 
 		$GLOBALS['TSFE']->applicationData['GMENU_LAYERS']['WMid'][]=$this->WMid;
 		$this->WMtempStore = $GLOBALS['TSFE']->applicationData['GMENU_LAYERS']['WMid'];