I had "backing off" issue on my GV connection too, here is what happened:
I upgraded to 1.2 a few days ago, everything was fine, then last night, I use the wizard to configure my local area code on the obi110 for GV, after that I start having the "backing off" problem, so I rebooted the box, after that, not only my GV have "backing off" problem, but my sipgate acct also failing authentication. (echo test works fine, call out via land line also works)
I rebooted my box a few more times, then I restored the config from a day ago, none of these help.
Finally, I reset the config to factory default then reconfig my GV acct info from scratch, problem solved
still not sure what the cause of the original problem, but at least, I have a working setup again