Index: imagecache.module
===================================================================
--- imagecache.module	(revision 189)
+++ imagecache.module	(working copy)
@@ -566,6 +566,10 @@ function imagecache_field_formatter($fie
     $item = array_merge($item,  _imagecache_file_load($item['fid']));
   }
 
+  // If there is not actual file to format, don't do it.
+  if ( $item['fid'] == 0 ) {
+    return;
+  }
 
   $parts =  explode('_', $formatter);
   $style = array_pop($parts);