I have been playing through without incident. Once in a while the screen will go black, the music goes into a half second loop repeat and the game goes to desktop, but I just click on the game and it lets me back in and I play on as before.

This time is different. At the NV Clinic, I choose an implant, say "here's the caps", and I start to fade away to black. That's when it freezes. I can control/alt/delete and shut the game off that way, but I've tried a few saves and the same thing happens.

I have all the DLC and one radio mod which allows me to play my own MP3 tracks. No other mods.

Any ideas?