This is the check list I give when incoming calls on your google voice number don't work.
The Obi will make outbound calls even if calling isn't completely set up on the gmail/google voice end.
Make sure:
1 - Chat is enabled in gmail
2 - Outbound Calling is enabled in gmail and the voice video plug in is installed
3 - You have made one successful outbound call from within your gmail account
4 - You have checked Google Chat as a forwarding phone in your google voice account
5 - Your gmail page is not open in a browser
6 - You are not running Talkatone, GrooveIp, or any other 3rd party app that uses your google voice account for calls.
7 - Make sure you can log into gmail using the same credentials you used to set up the account on the Obi.
Note: The Obion app does not sign in to your google account, so it will not affect your google chat status. It places calls directly through your Obi using the Obitalk Service.
All gmail and chat references above are for the same account you have set up on your Ob.