Graphics error in the launch menu?

I recently installed the portableapps suite and a few extra applications on my 1 Gb Sandisk USB drive. Works like a charm. However, the menu suffers from graphical glitches on my install, shown in the link below:

http://www.jonsolberg.se/repository/Misc/corruptedmenu.png

Main problems are the black areas and the fact that the "close" button is not where it's supposed to be (the Documents/Music/Movie/... menu also suffer from glitches: the "currently marked" is far to large).

At first I thought this was due to me having so many applications installed (since it seems like the menu size is fixed and does not adapt to the number of programs installed), but even though I removed a couple of them and restarted portableapps (to make the names fit on the menu list area) the problem remains.

Has anyone else experienced this problem? Any help appreciated.

Regards,
Jon Solberg