Windows 7: Photoshop CS4 Redrawing Issue

If I run Photoshop CS4 32-bit, not the 64-bit version, and enable advanced drawing and "use for image display" I get redrawing errors. I'm running the latest nVidia drivers on my 8800 GTS.

The strange thing is a bar flashes across my working image. It appears to be the image background pattern, the gray checker board, and it flashes only when I zoom in to 66.7%. Nothing else. And either my video card or hard drive starts making this awful grinding noise. If I zoom in more or out it stops. If I turn the features off it doesn't happen(not yet anyway).

Can someone test this? This worked fine in Vista and none of my hardware has changed. Just Windows. I suspect this might be an nVidia issue but I wasn't sure which forum to post it in. Feel free to move it of course!

Justin