I have a Lenovo slim desktop box , running windows xp 32 bit with a very basic on-board video card that runs on a Intel chip-set.
the problem is with the latest official 2.56 32 bit build. It does not occur on the 2.49b version.

After or during any render, if i move the rendering or any window across the ui , all the menu text becomes garbled and cannot be read at all. some text actually degrade as i watch for what is left of the menus. All the buttons are still there but most are illegible or completely blank. Even the tooltips are affected as well as any save/open message box.

It does not go away even after minimizing and expanding the window again. So far, closing and reopening blender is the only solution.