After enabling desktop effects I'm seeing corruption in the panel at the bottom of the screen. The symptoms are as follows.

If I move the panel to the sides the corruption disappears.

If I move the panel to the top I still get corruption.

If I create a new panel (with nothing on) I get no corruption, irrespective of where its located.

If the panel is redrawn, by moving it for instance the corruption disappears.

If I then swap workspaces the corruption reappears.

Only the blank area of the bar is corrupted (start button, clock, workspace switcher etc are not effected).

Has anyone seen similar problems or know of a fix?

I'm running SUSE 11 x86_64 with 8.5 fglrx on a X1950XTX @ 2560x1600.