Index: openbox-3.5.2/data/xsession/openbox-gnome-session.in
===================================================================
--- openbox-3.5.2.orig/data/xsession/openbox-gnome-session.in
+++ openbox-3.5.2/data/xsession/openbox-gnome-session.in
@@ -18,6 +18,9 @@ VER=$(gnome-session --version 2>/dev/nul
 MAJOR=$(echo $VER | cut -d . -f 1)
 MINOR=$(echo $VER | cut -d . -f 2)
 
+# use gnome menus (gentoo bug #291965)
+export XDG_MENU_PREFIX=gnome-
+
 # run GNOME with Openbox as its window manager
 
 if test $MAJOR -lt 2 || (test $MAJOR = 2 && test $MINOR -le 22); then