Some things don't work and will break every time. But once you get a CUDA error, nothing will work on GPU even if it's something that normally would have worked. Restarting Poser will clear that error and you'll be ok until you do something else that won't work. It won't prevent the original problem from occurring again though.

I have not been playing with P13 long enough to get a CUDA error yet, but I had quite a few in P12.