Thanks for all the info. It is indeed a virtualbox driver problem. I installed the vbox open-source drivers (virtualbox-ose-guest-utils and virtualbox-ose-guest-x11) and compiz now runs. (I had to reboot three times before the desktop appearance manager worked without crashing but it all seems fine now.)
Thanks for all the info. It is indeed a virtualbox driver problem. I installed the vbox open-source drivers (virtualbox- ose-guest- utils and virtualbox- ose-guest- x11) and compiz now runs. (I had to reboot three times before the desktop appearance manager worked without crashing but it all seems fine now.)