Index: image_helper.php
===================================================================
--- image_helper.php	(revision 13936)
+++ image_helper.php	(working copy)
@@ -170,6 +170,7 @@
 					'image/gif' => 'imagecreatefromgif:imagegif:gif',
 					'image/png' => 'imagecreatefrompng:imagepng:png',
 					'image/bmp' => 'imagecreatefrombmp:imagejpeg:bmp',
+					'image/x-ms-bmp' => 'imagecreatefrombmp:imagejpeg:bmp',
 				);
 
 				$mime_type = $image_info['mime'];