Index: workflow_access.module
===================================================================
--- workflow_access.module	(revision 2479)
+++ workflow_access.module	(working copy)
@@ -13,10 +13,9 @@
  * roles as access lists, so rids translate directly to gids.
  */
 function workflow_access_node_grants($account, $op) {
-  return array(
-    'workflow_access'       => array_keys($account->roles),
-    'workflow_access_owner' => array($account->uid),
-  );
+    $access['workflow_access'] = array_keys($account->roles);
+    if ($account->uid) $access['workflow_access_owner'] =array($account->uid);
+  return $access; 
 }