Although 0.53.3 changelog says it fixes this bug, it ain't true. Reopening.
** Changed in: update-manager (Ubuntu) Status: Fix Committed => Confirmed -- [Feisty] 0.53.3 depends on python2.4 https://launchpad.net/bugs/80976 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs