Comment 2 for bug 1076832

This is similar to bug 1058070. It might be reasonable for Synaptic to make Software Sources modal to it, if it was the only access point for Software Sources. But it is not. It has to be able to handle people making changes in Software Sources when that is opened from Ubuntu Software Center, Software Updater, or System Settings. In the same way, it should handle people making changes even when Software Sources is launched from Synaptic itself.

Separately, Software Sources should explain that it can't make changes when *anything* has locked apt, not just Synaptic.