Comment 4 for bug 274468

First off, this has been happening for a very very long time in mozilla, it seems unlikely the injection of ubuntu help will resolve things any time soon (although I could be wrong - certainly sqllite has taken over in other portions of the mozilla profile).

Secondly, I don't see this as just a localstore.rdf issue. The fact of replacing mozilla behind its back does cause the running firefox to behave oddly (File->Quit may not work, weird error dialogs may pop up) which is disconcerting to the users.
And there may be other effects. I don't see the harm in shutting it down beforehand instead of afterwards, and I see some immediate benefits.