Comment 10 for bug 218086

Just to be clear, this bug is about a much smaller issue than whether third-party repos should be supported during upgrade, on which I can see good points either way.

For a "real" distribution upgrade, kicked off by clicking the "new distribution version available" button in update-manager, you get a dialog saying that third-party sources will be disabled automatically, and you can reenable them through the software sources dialog. (Tested upgrading intrepid->jaunty.) I think just the same thing should happen during the 'partial upgrade' that update-manager sometimes runs, rather than it just aborting.