Another Windows Photo Gallery Problem

When I try to open Windows Photo Gallery in VISTA Ultimate, I get a transparent window with my desktop showing through. At least that's what it looks like until I move the window around and the background moves with it. Like it contains a snapshot of the background screen.

There's no sign of the photo it should be showing.

If I move another opened window across that window it leaves a trail of overlapping images of the moving window within the Gallery window.

I tried doing a roll-back without success.

Now I'm stumped.

I feel like there's a necessary process or service that's not running, but If that's true, I don't know which one.