Comment 3 for bug 625628

If you can view individual sources in USC, you should be able to add them and remove them there too. However, I don't know yet whether that would mean removing those settings from Software Sources. *Maybe* they should be in both places. If so, then removing a source should be something handled by aptdaemon, presenting an interface for you to specify which packages you want to downgrade or remove. Maybe aptdaemon is the right place for that regardless.