So now that you know how to get Compiz working properly, what do you do if it still refuses to enable itself via the “Desktop Effects” program?
Justin had this exact problem on his machine. It appears that the compiz-gtk script wouldn’t start and my theory was that it’s unable to replace Metacity (for some reason).
So I fixed this by editing his gconf file directly
sed -i 's/metacity/compiz-gtk/' \
This means that Metacity is never loaded to begin with, instead calling compiz-gtk to do its magic.
This is exactly what is set after successfully enabling Compiz via the “Desktop Effects” program, so we’re just bypassing whatever problem was stopping it from being enabled (like I said, I think it was unable to replace Metacity).
If you have the same problem, try this fix. If it can’t start Compiz it will safely revert to Metacity.