Index: upload_formatter.php
===================================================================
--- upload_formatter.php	(revision 15455)
+++ upload_formatter.php	(working copy)
@@ -93,7 +93,7 @@
 		}
 
 		if ( is_array($value) && count($value) > 1 && $value['size'] ) {
-			if ( is_array($value) && $value['error'] === UPLOAD_ERR_OK ) {
+			if ( is_array($value) && (int)$value['error'] === UPLOAD_ERR_OK ) {
 				$max_filesize = isset($options['max_size']) ? $options['max_size'] : MAX_UPLOAD_SIZE;
 
 				// we can get mime type based on file content and no use one, provided by the client