Index: typo3/sysext/cms/tslib/class.tslib_fe.php
===================================================================
--- typo3/sysext/cms/tslib/class.tslib_fe.php	(revision 4479)
+++ typo3/sysext/cms/tslib/class.tslib_fe.php	(working copy)
@@ -250,6 +250,7 @@
 	var $loginUser='';					// Global flag indicating that a front-end user is logged in. This is set only if a user really IS logged in. The group-list may show other groups (like added by IP filter or so) even though there is no user.
 	var $gr_list='';					// (RO=readonly) The group list, sorted numerically. Group '0,-1' is the default group, but other groups may be added by other means than a user being logged in though...
 	var $beUserLogin='';				// Flag that indicates if a Backend user is logged in!
+	var $beUserUid = 0;					// UID of Backend user if logged in
 	var $workspacePreview='';			// Integer, that indicates which workspace is being previewed.
 	var $loginAllowedInBranch = TRUE;	// Shows whether logins are allowed in branch
 	var $ADMCMD_preview_BEUSER_uid = 0;	// Integer, set to backend user ID to initialize when keyword-based preview is used.
Index: typo3/sysext/cms/tslib/index_ts.php
===================================================================
--- typo3/sysext/cms/tslib/index_ts.php	(revision 4479)
+++ typo3/sysext/cms/tslib/index_ts.php	(working copy)
@@ -272,6 +272,7 @@
 		if ($BE_USER->user['uid'])	{
 			$BE_USER->fetchGroupData();
 			$TSFE->beUserLogin = 1;
+			$TSFE->beUserUid = $BE_USER->user['uid']; 
 		}
 		if ($BE_USER->checkLockToIP() && $BE_USER->checkBackendAccessSettingsFromInitPhp() && $BE_USER->user['uid']) {
 			$BE_USER->initializeFrontendEdit();
@@ -296,6 +297,7 @@
 	if ($BE_USER->user['uid'])	{
 		$BE_USER->fetchGroupData();
 		$TSFE->beUserLogin = 1;
+		$TSFE->beUserUid = $BE_USER->user['uid'];
 	} else {
 		$BE_USER = '';
 		$TSFE->beUserLogin = 0;
@@ -323,7 +325,8 @@
 			// Remove user
 		unset($BE_USER);
 		$TSFE->beUserLogin = 0;
-
+		$TSFE->beUserUid = 0;
+		
 			// Re-evaluate the page-id.
 		$TSFE->checkAlternativeIdMethods();
 		$TSFE->clear_preview();