Which sync method are you using, MobileMe, Bonjour, or Advanced? Have you tried just letting the thing spin until it times out? You might also try visiting
http://people.omnigroup.com/kc/Debug...tKeychain.html to reset the password to see if that might be the root cause. You also should send email to
omnifocus-iphone@omnigroup.com so that someone at Omni will start working on this problem with you if we don't get it figured out.