In 12.04, install 'gnome-panel', which will add the "Classic Gnome (no effects)" option. Boot into that and it'll give you a metacity window manager environment without compositing. You can verify that metacity compositing is off as so:
$ gconftool-2 -g '/apps/metacity/general/compositing_manager' false
In 12.04, install 'gnome-panel', which will add the "Classic Gnome (no effects)" option. Boot into that and it'll give you a metacity window manager environment without compositing. You can verify that metacity compositing is off as so:
$ gconftool-2 -g '/apps/ metacity/ general/ compositing_ manager'
false