Check what software version is on your OBi by logging in to its local web interface. The 'Product Information' section shows it.
If it is not 1.3.0 (Build: 2886) you should update it manually.
https://www.obitalk.com/forum/index.php?topic=9.msg13#msg13, option 3.
Then you need to reconfigure GV using the Obitalk forum. Try the procedure in the last bullet point at
http://www.obitalk.com/forum/index.php?topic=11384.0. If that does not work use the fuller procedure linked to at the end of that post.