HELP "Unspecified driver error"

Hi all

I am trying to make a simple FEM solver on GPU. Recently my code started to return an error “unspecified driver error” every time I try to do anything with GPU memory (like cudaMalloc). It crushes down even when I run examples like fluidsGL even though it used to work fine 2 days ago. On the other hand when I run simpleD3D it works however window content is all black.

I wonder if you have encountered such problem before? Do you have any idea what might be the reason or how to troubleshoot it?

I work on Windows XP and use GeForce 8800 GTS 640MB.