I'm quite new to Ubuntu, and I don't know how to fix this:

I have been experiencing the problem with window decorations that go away. I have been told that I could correct that with compiz fusion icon, just restarting the graphics whenever it happened. This solution only fixed the problem for like 30 seconds.

Then I found out that the command inside the window decorator had changed, so I only had to reset it to default (/usr/bin/compiz-decorator). The only problem is that it keeps changing the command by itself once or twice a day.

I can live with that, but I would like to find a more permanent solution, if there is one.

I am running Ubuntu 11.10