Comment 18 for bug 152264

The easy solution is to change the following in Compiz:
window-decoration -> shaduw = "!(type=Dock)" (see attachment, which in Dutch if you don't understand). Personally this made me happy, since I do not like the shadow of the upper panel. As you might have figured out, the actual bug is not fixed with this cover-action.

Maybe interesting: If I change anything in this screen, the shadow disappears (in other words: is built up with the current information about the windows). This tells me Compiz is not updated correctly when dock-windows get a different state. Messed up listener?