Did you try unrestricting the Phone application, since FaceTime resides within it? Or is that what you did originally.
Just tried facetime using my3g with my wife. It was pretty darn smooth. Voice quality was excellent also. Finally we don't need to use Fring anymore. The video chat on that was horribly bad.
I've seen the screen capture of the "working face time" from the dev. This is a screenshot just before connecting to a FaceTime conversation. Does anyone have a screenshot of an actual conversation happening using 3gU?
The reason that is done is because once the facetime call is stablished you cannot see the top bar.