Hi

Don't know if it will help and I am using a GTX 285. But the 182.50 has giving me the best results across the board of any I have tried. I have run into a few issues here and there with the newer ones. Might be worth a shot.
Win7 x64 users can use the Vista x64 version (they do not have that driver listed for Win7, since it was released before Win7 was). It works perfectly fine with Win7 x64 though