If you have a Samsung Vibrant running CyanongenMod, then you probably want to flash a a stock-based ROM double-quick. Why? Because you can't call 911 while running CM on this particular device. Sure, you may not remember the last time you had to call 911 (if ever), but can you imagine what would happen if you were in a situation where you needed to call 911 and couldn't?
For this exact reason, the CM team has decided to drop support for the Vibrant. The issue could be resolved with the radio source from Samsung, so if Sammy ever decided to release this code, there is a chance that CM could pick up support for the Vibrant again.
We are no longer supporting the Vibrant due to the inability to dial 911. We consider the issues related to this unresolvable without source code from Samsung related to the Radio interface layer and its interactions with the Audio layers and have taken the decision to no longer support this. We apologize for the inconvenience and strongly suggest that Vibrant users use a Samsung ROM due to the 911 issues with any ROMs based on open source code.
-SGS Team/Team Hacksung/Teamdouche
Sorry, Vibrant owners, but this one is probably for the best.