Solved for me. Looks like the language-support-input-ja package is causing the problem. Could you post your /var/log/dist-upgrade/main.log?
** Changed in: update-manager (Ubuntu) Status: Confirmed => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/772459 Title: Update to 11.04 "Could not Calculate the upgrade" -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs