After my PC has been on for a bit (15mins?) some of my windows start displaying see-through properties and other bizarre characteristics (like being able to draw on each other with by dragging the windows over other windows).
Now, this PC is a Core2Quad, 4GB system with Windows XP SP3 32bit. The graphics are 128MB PCI NVidia.
Below you can see a screenshot of a Ubuntu session in Virtualbox showcasing this:
However, any and every window can do this. Chrome, Firefox, OpenOffice, anything that is a window occasionally pops-up see-through. Most the time it happens when I minimize a window and then pull it back up later. So perhaps some re-draw based on the memory isn't happening.