Index: trunk/core/kernel/utility/formatters/upload_formatter.php
===================================================================
diff -u -N -r6797 -r8074
--- trunk/core/kernel/utility/formatters/upload_formatter.php	(.../upload_formatter.php)	(revision 6797)
+++ trunk/core/kernel/utility/formatters/upload_formatter.php	(.../upload_formatter.php)	(revision 8074)
@@ -140,7 +140,7 @@
 		$new_name = $filename.$ext;
 		while ( file_exists($path.'/'.$new_name) )
 		{
-	   		if ( preg_match("/({$filename}_)([0-9]*)($ext)/", $new_name, $regs) ) {
+	   		if ( preg_match('/('.preg_quote($filename, '/').'_)([0-9]*)('.preg_quote($ext, '/').')/', $new_name, $regs) ) {
 					$new_name = $regs[1].($regs[2]+1).$regs[3];
 				}
 				else {