I experience occationally (quite often, but not consistent) that the display driver crashes and restarts when I have a PDF open in Adobe Reader (version 9.4.5).
My display is NVIDIA. I also have 2 monitors.
I found an answer in a thread on Adobe Forums that so far seems to have fixed the issue.
I have tested to turn it on and off, and it seems like it crashes if I have two pdf documents opened and then scroll. This only happens when 2D acceleration is turned on, so turning that off seems to fix this problem.