Re: 275.09.07 driver
I am not sure if I understand right. Did you try the ports drivers successfully after failing with 275.09.07? If not, did you take care about synced kernel and kernel sources (often kernel sources are newer than the installed kernel itself)?
If nothing else helps, please try the following:
- build and install new kernel (and perhaps world)
- rebuild and reinstall nvidia-driver
Hope this helps.