Installed Windows Vista 32bit Premium. DirectX 10 and WHQL 20 december NVIDIA drivers. Tried the Car demo just for fun and it runs great. So tell me how can I replicate your problem? With the trial installed on my computer WED about box displays: Trial 7.06 V6.84

Guess you could try to use the current trial version from the download page. Maybe your trial 7.05 V6.835 is bugged. Also doing this may void your trial period, so please think about this before you take the step!