Index: core/mail_api.php
===================================================================
--- core/mail_api.php	(revision 1002)
+++ core/mail_api.php	(working copy)
@@ -35,8 +35,6 @@
 		'IMAP' => array( 'normal' => 143, 'encrypted' => 993 ),
 	);
 
-	private $_file_number = 1;
-
 	private $_validated_email_list = array();
 
 	private $_mail_add_bug_reports;
@@ -729,8 +727,6 @@
 			{
 				$t_rejected_files = NULL;
 
-				$this->_file_number = 1;
-
 				foreach ( $p_email[ 'X-Mantis-Parts' ] as $part )
 				{
 					$t_file_rejected = $this->add_file( $t_bug_id, $p_email[ 'Reporter_id' ], $part );
@@ -787,12 +783,14 @@
 		}
 		else
 		{
-			while ( !file_is_name_unique( $this->_file_number . '-' . $t_part_name, $p_bug_id ) )
+		  $file_number = 0;
+		  
+			while ( !file_is_name_unique( $t_file_name = (($file_number > 0)? preg_replace('/(\..+)$/', '-'.$file_number.'$1' , $t_part_name) : $t_part_name), $p_bug_id ) )
 			{
-				$this->_file_number++;
+				$file_number++;
 			}
 
-      $t_file_name = $this->_mail_tmp_directory . '/' . $this->_file_number . '-' . $t_part_name;
+      $t_file_name = $this->_mail_tmp_directory . '/' . $t_file_name;
 
 			file_put_contents( $t_file_name, $p_part[ 'body' ] );
 
@@ -824,8 +822,6 @@
 			{
 				unlink( $t_file_name );
 			}
-
-			$this->_file_number++;
 		}
 
 		return( TRUE );