Graphic glitches in the dropdown menu

[SanskritFritz <sanskritfritz gmail com>]

This has been for a while, now I gathered some screenshots for a report. I'm not sure Kupfer is to blame, but this doesnt happen with any other program I use. I'm using Compiz standalone. See the pictures at this link:

http://www.wuala.com/SanskritFritz/Public/WualaScreenshots/

The first pic is ok, this is how kupfer looks. After displaying a submenu with only one element and pressing left to return to the previous menu, the dropdown list starts to tear, as you see on the screenshots. After a few ups and downs it normalizes again. Kupfer is fully functional at all stages.