I have just updated to Ubuntu 11.10 and I am using unity 2d. My terminal applications (gnome-terminal or konsole) just won't go into background. When I move another application in front of them, they are still rendered, but the clicks are going through them. This behavior only appears when the terminal windows interact with another applications. I can move one terminal over another without a problem, but even the menu list of a terminal application can not be shown, since it is - for some unknown reason - "behind" the terminal.

Any ideas what might be the cause of this problem?

I do not have this problem with my other machines. The only difference is, that I am using unity 2d here and ("normal") unity at home.