|in vista, click the window button, then put the mouse over computer|
right click and select properties
Then use the device manager task
hit the plus for display adapters, and ensure you do not have on board video card enabled, only the sub header for your video card.
then double click the video card name, and under the driver tab, hit the update driver button. That is what fixed it for me, even though I downloaded the new drivers a couple days before.
the link above is a thread I started on starcraft forums.