I believe I've fixed this in gparted 0.2.5-1.1ubuntu1 in edgy by correcting the menu index calculations in various places.
** Changed in: gparted (Ubuntu) Assignee: (unassigned) => Colin Watson Status: Confirmed => Fix Released -- "Unmount" and "Deactivate" not disabled properly https://launchpad.net/bugs/45653 -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs