I read about a guy who had a similar problem, so what the sleep lab did was let him wake and sleep as he wanted to.
Gradually he got totally out of phase with daylight but then eventually he got back in phase and the problem left him.
The trick was letting this condition take its course so he was once again in sync with normal day/night rhythms.
Dunno' if it works for everybody.
http://en.wikipedia.org/wiki/Dyssomnia