As I said it in FurMark’s changelog, there is an issue under Vista with ForceWare drivers.
From this topic @ driverheaven.net, the problem seems to come from Aero-Glass and the workaround is to disable Aero-Glass for FurMark:
– right-click FurMark icon
– select tabulator “compatibility”
– tick the checkbox as seen in screenshot (whatever it’s called in your language)
– this disables “aero-glass” only for FurMark