Hello.
I followed this guide to install compiz on debian unstable: http://wiki.debian.org/Compiz (and other 2 little guides not in english) but when I launch from shell "compiz --replace &" window borders vanishing and windows are not more clickable. I use nvidia 5700 with last drivers available on unstable repository. Have you any idea?
Unlike most other window managers, compiz does not draw window borders. Instead, drawing window borders is handled by "gnome-window-decorator" or "gtk-window-decorator". You should start that before compiz. Hope that helps... Daniel Foote.