Index: acidfree.module
===================================================================
--- acidfree.module	(revision 249)
+++ acidfree.module	(working copy)
@@ -1972,12 +1972,17 @@
 }
 
 function acidfree_filemanager_download($file) {
+    // if it is not an acidfree file, allow some other module to test
+    if ($file->area != "acidfree")
+        return null;
+
     // Tedious way to get original node id given an fid in file
     $nid = db_result(db_query("SELECT nid FROM {node} ".
             "INNER JOIN {acidfree} ON {node}.nid = {acidfree}.aid ".
             "WHERE {acidfree}.large = %d OR {acidfree}.small = %d ".
             "OR {acidfree}.thumb = %d", $file->fid, $file->fid, $file->fid));
     $node = acidfree_get_node_by_id($nid);
+
     // allow for temporary files to be viewed (needed for previews)
     if (!$node && $file->working)
         return true;