This only happens if you already started an administrative application (from System -> Administration) before and already entered your password in gksudo. This is the very same behaviour as on the console, sudo doesn't ask for the password for 5 minutes after you successfully authenticated once.
Since the authentication ticket applies to a particular terminal, you might have different tickets in gnome terminals than on the desktop. ** Changed in: meta-gnome2 (Ubuntu) Status: Unconfirmed => Rejected ** Visibility changed to: Public ** This bug is no longer flagged as a security issue -- Critical security problem in ALT+F2 (run program) and sudo! https://launchpad.net/bugs/52652 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs