HUGE Bandwidth Consumption, Even When Not Being Used

All of a sudden, my OBI200 is consuming 2 MB/s bandwidth, even when there's nothing going on. It's FAR more than even streaming TV over the internet.

I checked my router, and sure enough, it's all going downstream to the OBI. When I unplug the OBI or its network cable, it stops. When I plug it in again, it starts right back up. I did it three or four times to be sure. I checked the Obitalk configuration site and there's no indication that it is updating or anything.

Here's a potential clue. I had Google Voice set up as the outbound primary line and voip.ms also set up. I deleted the Google Voice from the OBI2 configuration and the bandwidth settled down. THEN I noticed that the VOIP.MS had not automatically taken over as the primary outgoing line. When I checked that box for the VOIP.MS setup in the OBITALK site, the data consumption started right back up. It's now unplugged physically till I can figure it out.

Comcast recently imposed a 1 TB a month limit and, although my typical usage had been about 300 gb a month till now, I've now consumed 900 gb in only 8 days due, primarily to this.

Any ideas what might be causing my OBI to be so data-hungry all of a sudden?

Thanks

Dennis