Ok so I thought I'd put up a thread as I'm new to the team with CPU results and I just installed the GPU client last night. I'm running Windows Vista X64 and the 177.26 beta drivers running on two 8800GTS 640mb in SLI (set in control panel too) and I'm not experiencing any issues with completing work units or starting new ones. In the F@H forums quite a lot of people are getting early work unit end with the 174.55 on Vista X64. Give the 177.26 or .35 a whirl and see how they pad out. Currently burning through work units like a champ Go Nvidia !