For anyone who was wondering what the resolution was . . . here you go.
During the entire time that I could not launch Google Talk, I had a low memory warning. I went through my apps and deleted a couple that I don't use too often, and used Quick App Manager to clear all caches.
That cleared the memory error and all of a sudden my status indicators turned green again. And, I could open Talk.
End of story.
It is very annoying that the N1 has such paltry memory. Now considering an upgrade.
aviduser