Occasionally, you'll get an assertion in the RDF service from an RDF/XML datasource that is being destroyed. This happens because an RDF/XML datasource is created, tries to register itself, and fails. Then, the factory method destroys it, and we get an assertion when the datasource tries to unregister itself. I've removed the assertion from the RDF service (this seems like a common pattern -- might as well make the service deal with it gracefully), and added some checks to make sure that the datasource that was actually asking to be unregistered matches its URI key.
rjc: could you code review the patch?
this could affect sidebar, flash panel, local store and persistence. these need to be tested.