Driver file gone

Ok so I am writing Cuda code on an Ubuntu 8.04. Everything has worked up until tonight. Now I get the error:

NVIDIA: could not open the device file /dev/nvidia0 (No such file or directory)

I checked in the devices and I have a nvidia1 file but the nvidia0 file is gone? It was there yesterday.
I am working through terminal and the file is gone as root so it’s not a permissions problem.

I did a sudo lshw -C video and see all four of my video cards…

I am pretty green to linux. Can I get the nvidia0 file back without completely re-installing the driver?

Thanks so much,