I'm having the same problem with my OBi 100. Exactly once every hour - to the minute - the obi device signs into the google account I configured for it.
What makes matters worse is that this automated signin activity
is preventing me from using that google account for other legitimate activities. For example, when I attempt to authenticate another application (via oauth) to access certain pieces of my account data, Google prevents me from doing so with the error message:
Our systems have detected unusual traffic from your computer network. Please try your request again later. Why did this happen?
IP address: xxxx
Time: xxxx
URL: http://accounts.google.com/OAuthAuthorizeToken
So I've had to unplug my obi until I find a remedy. I know it's the obi that's doing this because when I unplug it, the hourly google signins stop. Even stranger, the obi appears to be spoofing a "Firefox 9.0" browser header - to see this just login to "accounts.google.com", go to Security / Recent Activity, click a particular signin event, and look at the event details.
Google Voice and my ObiTalk OBi 100 are completely useless because my obi keeps signing in exactly every hour, which Google Accounts sees as "unusual traffic" from my computer network, which results in Google blocking certain account activities - such as OAuth authorizations for other legitimate applications!

Is OBi Tech Support reading this forum? Please help with this problem.