Welcome to JustAnswer. Is your phone an OBI
A recent issue with the OBi 100/110 devices' firmware is causing your problem. You need to update the firmware to continue using it with Google Voice.
You may need to re-authorize your device to use your Google account after this procedure. To do that, first, be sure that you are logged into the correct Google/Gmail account that holds your Google Voice number. Then, open another web browser tab, and log into to the OBiTALK dashboard, click on your device, then click on the Service Provider (SP1 or SP2) that is using Google Voice. Click "Accept" at the prompt. On the window that will open, click the link to "Replace Google account credentials" and follow the instructions.
If your device still doesn't work after this procedure, I recommend following the complete set of instructions, on the first page of this discussion topic: http://www.obitalk.com/forum/index.php?topic=8560.msg56460#msg56460
Let me know how it goes.