Index: filefield_widget.inc
===================================================================
--- filefield_widget.inc	(revision 906)
+++ filefield_widget.inc	(working copy)
@@ -236,6 +236,11 @@
     // Load file if the FID has changed so that it can be saved by CCK.
     $file = field_file_load($item['fid']);
 
+    // If the entry exists, but the file is no longer available, field_file_load returns FALSE
+    if (!$file) {
+      $file = array();
+    }
+
     // If the file entry doesn't exist, don't save anything.
     if (empty($file)) {
       $item = array();