For me both disable_lock_screen and disable_log_out options works as supposed on current Jaunty - but only for main menu, on fast-user-switch-applet (in top right corner by default) this has no effect - which is clearly bug 358565.
For me both disable_lock_screen and disable_log_out options works as supposed on current Jaunty - but only for main menu, on fast-user- switch- applet (in top right corner by default) this has no effect - which is clearly bug 358565.