Windows 7 moving Windows style changed

This isn't a desperate problem but one that is annoying me nonetheless. For some reason when I drag windows around the desktop on Windows 7 it only gives me an outline instead of the normal full window moving. This has changed by itself, any ideas how to get it back to normal?

I've tried switching themes but that didn't help :( If you don't understand what I mean I've attached a picture.

img16.imageshack.us/i/movingwindows.png
 
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