A metacity theme defines a style_set for each of the "normal", "dialog", "modal_dialog", "utility", "menu", and "border" kind of window. With Compiz enabled, the "normal" style_set is used for all kinds of windows, and the window decorations aren't even drawn for detached menus ("menu" kind, in Gimp for example).
I'm using Gnome on Mandriva 2008.0.
$ rpm -qa | grep -v devel | grep -E 'xorg|compiz|metacity' | sort
Mass closure: This bug has been untouched for more than six years, and is not
obviously still valid. Please reopen this bug or file a new report if you continue to experience issues with current releases.