When I launch bitcoin gui client under KDE (Fedora 14) with option minimize to system tray, it generates lot of blank spaces there.
Each time I maximize client, it disappears from tray, but leaves a blank space where it was.
Then I minimize client, and bitcoin icon in tray appears in a new position.
So the result you can see here:
http://img594.imageshack.us/i/btcbug.jpg/
This is not happen when bitcoin GUI not running.