10.6.6

I've been using a Geforce 7950 GT with dual displays and having great success. I recently upgrade to a GTX 460. The first time I booted up to one display at 1024x768. I installed the most recent NVIDIA drivers (Retail_256.01.00f03v5) and it restored my displays.

Now everything is working great except it crashes after an hour or two. Ideas?