This is not just happening in a Dapper->Edgy update. I have just done a fresh install of Knot 3 and I have encountered the same issue after my first 'apt-get update && apt-get dist-upgrade'. Aptitude seems to work around part of the problem, but does not fix it completely.
-- Error during Dapper-->Edgy update, problem removing python2.3 https://launchpad.net/bugs/56779 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs