nvidia device files

I recently installed CUDA 3.0 drivers and everytime I reboot the machine, the files in /dev directory (the device files) are deleted.

I get this when I tried to use NVIDIA’s System Management Interface (nvidia-smi)
NVIDIA: could not open the device file /dev/nvidiactl (No such file or directory)

As well as when I run deviceQuery, it is unable to find a GPU.

I read from the release notes that the /dev/nvidia(x) entries are created using startx or using the script (possibly added to /etc/rc.local?). What is the best way to do this everytime I reboot?