This is fixed in the feisty version of the dist-upgrader (it will protect against ValueErrors from python-apt.
** Changed in: update-manager (Ubuntu) Status: Confirmed => Fix Released -- Dapper upgrade to Edgy: Frozen dist-upgrade and failed second run (in Finnish locales https://launchpad.net/bugs/68553 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs