Funny that this other post came up. Here is the opposite of your experience. Obvious conclusion is that YMMV.
Hmm. That's not how I read it.
What he said:
After installing the Obi with Google Voice, all works perfectly except that when I'm signed in to Gmail and receive an inbound call, my PC doesn't ring, only the physical phone rings.
What I said:
In practice, it seems like the OBi and gtalk are cooperating nicely, as long as I don't expect gtalk to ring on incoming calls.
I don't see our M Ving at all -- it sounds like we're seeing the same thing. The only difference is that @Spotlight over there sees it as a problem that his PC doesn't ring, and I don't. I just want to make sure that my
outgoing gtalk webcalls will continue to work. Sounds like nobody knows for sure.