--- user.module	2008-02-11 04:06:13.000000000 +0000
+++ user.module	2008-03-27 12:40:47.000000000 +0000
@@ -309,6 +309,9 @@ function user_validate_picture($file, &$
 
   if (!form_get_errors()) {
     if ($file = file_save_upload('picture_upload', variable_get('user_picture_path', 'pictures') .'/picture-'. $user->uid .'.'. $info['extension'], 1)) {
+      // Remove the old picture.    
+      file_delete($user->picture);
+      
       $form_values['picture'] = $file->filepath;
     }
     else {