Just completed the "Ghost Town gunfight" quest and as a result the Powder Gangers vilified me and hate me. So i had NCR (Neutral) and Powder Gangers (Vilified), From there is went straight to Primm and did the "my Kind of Town" side quest and saved the sheriff. Once outside the hotel i was given the choice of who to ask to be the law of the town. I checked my reputation again and the NCR one is missing, and the Powder Gangers is now neutral.
So why has the NCR reputation vanished, and why dont the Powder Gangers hate me anymore, even tho i did nothing to help them out?