I have the same issue in my Dell 12.04 . But I have observed that if I turn off the wireless and then shutdown , it works fine. Also "sudo poweroff" also works for me.
I have installed "firmware-b43-lpphy-installer" for my Wireless card as its Broadcom Corporation BCM4312 802.11b/g LP-PHY [14e4:4315] card -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gnome-session in Ubuntu. https://bugs.launchpad.net/bugs/987220 Title: no complete shutdown To manage notifications about this bug go to: https://bugs.launchpad.net/indicator-session/+bug/987220/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
