KWin is not restored after removing Compiz

I tried Compiz on a desktop computer, but this made the system pretty slow, so I removed it with synaptic... after a restart, all the windows of the KDE desktop were shown without a frame (thus it was pretty useless). This seems to be a known bug in (k)ubuntu, but the solution

sudo aptitude reinstall kwin

did not work for me (all the windows were still frameless).

The only solution that worked for me was also to remove all the compiz configuration files in my home:

find ~/ -name "*compiz*" -exec rm -rf {} \;

hope this helps :-)