Index: units/helpers/file_helper.php
===================================================================
--- units/helpers/file_helper.php	(revision 14888)
+++ units/helpers/file_helper.php	(working copy)
@@ -428,25 +428,31 @@
 			$parts = pathinfo($name);
 			$ext = '.' . $parts['extension'];
 			$filename = $parts['filename'];
+			$path = rtrim($path, '/');
+
+			$original_checked = false;
 			$new_name = $filename . $ext;
 
 			if ( $parts['dirname'] != '.' ) {
-				$path = rtrim($path, '/') . '/' . ltrim($parts['dirname'], '/');
+				$path .= '/' . ltrim($parts['dirname'], '/');
 			}
 
 			// make sure target folder always exists, especially for cases,
 			// when storage engine folder is supplied as a part of $name
 			$this->CheckFolder($path);
 
-			while ( file_exists($path . '/' . $new_name) || in_array(rtrim($path, '/') . '/' . $new_name, $forbidden_names) ) {
-				if ( preg_match('/(' . preg_quote($filename, '/') . '_)([0-9]*)(' . preg_quote($ext, '/') . ')/', $new_name, $regs) ) {
-					$new_name = $regs[1] . ($regs[2] + 1) . $regs[3];
+			do {
+				if ( preg_match('/(.*)_([0-9]*)(' . preg_quote($ext, '/') . ')/', $new_name, $regs) ) {
+					$new_name = $regs[1] . '_' . ((int)$regs[2] + 1) . $regs[3];
 				}
-				else {
+				elseif ( $original_checked ) {
 					$new_name = $filename . '_1' . $ext;
 				}
-			}
 
+				$original_checked = true;
+				$res = file_exists($path . '/' . $new_name) || in_array($path . '/' . $new_name, $forbidden_names);
+			} while ($res !== false);
+
 			if ( $parts['dirname'] != '.' ) {
 				$new_name = $parts['dirname'] . '/' . $new_name;
 			}