New driver, 186.08, same issue
still listed under Known Issues for Vista X64.
GeForce 200 Series: When entering custom resolution values from the Manage
Custom Resolutions page, the values are not validated. [524691]
http://uk.download.nvidia.com/Windows/186.08/186.08_WinVista_GeForce_Release_Notes.pdf
I truely hope Matrox are at least raising the profile of this problem, nVidia have effectively left TH2G dead in the water due to their driver inadequacies. To think it was working and they broke it, months ago and left it broke. :evil:
PS: I will test it myself anyway, I guess.