Radeon mem map fix (#2): Need regression tests please

[Roland Scheidegger]

Roland Scheidegger wrote:
> invisible). Also, some icons on the kde background simply aren't drawn,
> and 3d apps cause permanent damage to the background image. The
> "classic" xawtv overlay also doesn't work at all (black window).
not only 3d windows cause this - any window destroys the background 
image (at the place it's drawn).

Roland