In virtually every compiz tutorial you read on the net you will find the following advice on starting compiz when you log in:
Open System -> Preferences -> Sessions and add “compiz --replace” to the startup programs list.
That is wrong and it should be expunged from the internet IMHO. If you do that, your GDM will first start metacity, then start nautilus (desktop) and gnome-sesssion-manager, which in turn will start compiz. So you’re starting one window manager only to replace it with another shortly afterwards. You can see this clearly because it takes a while for compiz to start up and load your window decorator (like emerald) after replacing metacity.
The proper way to do this is to tell Gnome to use compiz as your default window manager and not use metacity at all. Simply put this in your ~/.gnomerc (create that file if it does not exist yet):
- export WINDOW_MANAGER=/usr/bin/compiz
Spread the word!