does DigiTest recognize your cards?? If you run Digitest, does anything fail? It's a long shot, but you should check to see if the firmware is up to date on your I/O (in Digitest). I've seen this error when everything was connected properly, but the interface wasn't delivering a solid clock down the digilink. Make sure your I/O are not looking for external sync that isn't there. If you have multiple interfaces, try removing all but one until you diagnose the problem. - Borg