Also crashes for me, but works when I right-click on the orange notification icon and select "Install all updates." It has crashed twice and then worked with the right-click both times.
** Attachment added: "crash log" http://librarian.launchpad.net/5769211/_usr_bin_update-manager.1000.crash -- update-manager crashed in feisty https://launchpad.net/bugs/79274 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
