Help! Unsolved problems with maximized Kubuntu Intrepid windows

After quite happily having upgraded to Intrepid on two machines (a laptop and a desktop), I started upgrading a second laptop. By now, I had apt-p2p installed on my first laptop, and with the help of Cameron hacked apt-p2p to allow my laptop use the apt-p2p installation of my already migrated laptop. The download went rather smoothly. Anyway, that's not important to my problem.

The problem I encountered with my second laptop, after fixing the ATI-driver problem (I had to replace to old ATI drivers with the new opensource driver package to get X11 working again), was that all windows automatically maximized:

When I minimize the window, it does, but does not have any decoration:

There is little to find with Google, except for this closed thread on ubuntuforums. I followed hints.

I removed my .kde folder, made sure I was using kwin, checked window size settings (but it even maximizes dialogs!), and Riddel was kind enough to make some suggestions, which unfortunately did not help either. Worse, I rebooted my already migrated laptop, and now I have the problem on both laptops :(

So, at least the problem is not hardware related. Also, the most recent updated laptop showed the problem with both KDE 4.1.2 and 4.1.3, so that does not seem to be the problem either. A reboot triggered the problem of my first migrated laptop, which was last booted 4 days ago. So, it seems to have to do with a package I installed upon the upgrade of the second machine, and which I installed in the last 4 days... does aptitude keep a log by now?

The problem is rather annoying, and makes the desktop quite unusable... I don't want to reinstall Intrepid from scratch... I filed a bug report with some extra details. so, if you have any suggestion, any, I am likely going to try it. Any suggestion on how to debug the problem is also most welcome...

Update: problem could be fixed with: aptitude remove devilspie. Thanx to all who replied!