Index: t3lib/class.t3lib_extfilefunc.php
===================================================================
--- t3lib/class.t3lib_extfilefunc.php	(revision 6203)
+++ t3lib/class.t3lib_extfilefunc.php	(working copy)
@@ -688,7 +688,7 @@
 		if (!$this->isInit) return FALSE;
 
 		$theFolder = $this->cleanFileName($cmds['data']);
-		if (isset($theFolder))	{
+		if (isset($theFolder) && trim($theFolder) != "")	{
 			if ($this->checkFileNameLen($theFolder))	{
 				$theTarget = $this->is_directory($cmds['target']);	// Check the target dir
 				if ($theTarget)	{