I have the same processor but an inferior graphic card (8400 GS). I have 8GB RAM and Vista 64 Home Premium. The comparison XP64 versus Vista64 was vividely discussed in at least one thread, you can do a search and read about it, I remember there were some interesting points of view.

Are you sure you have your Vue display options correctly set up? Your symptoms are so strange that something seems wrong, it doesn't seem caused by the operating system. It would be interesting to see a screenshot of your Vue display options.

But I think we shouldn't discuss these things in this thread, it's off-topic. I suggest that you create a separate thread. :-)