Index: workflow.module
===================================================================
--- workflow.module	(revision 223)
+++ workflow.module	(working copy)
@@ -449,7 +449,13 @@
 
   // Make sure this transition is valid and allowed for the current user.
   global $user;
-  if ($user->uid > 1 || $user->uid == 0) { // allow any state change for superuser (might be cron)
+
+  // If we are executing a cron job, we shouldn't check the permissions
+  // as cron is executed as a anonymous user but the transition can only be scheduled
+  // by an authorised user
+  $cron = $_SERVER['REQUEST_URI'] == base_path() . 'cron.php' ? TRUE : FALSE; 
+
+  if (($user->uid > 1 || $user->uid == 0) && !$cron) { // allow any state change for superuser and for cron
     $tid = workflow_get_transition_id($old_sid, $sid);
     if (!$tid) {
       watchdog('workflow', t('Attempt to go to nonexistent transition (from %old to %new)', array('%old' => $old_sid, '%new' => $sid), WATCHDOG_ERROR));