Looking at your discussion from April,
http://www.obitalk.com/forum/index.php?topic=9854.msg65296#msg65296I suspect that you've made multiple changes, based on advice from others, and now your device is just a mess. I would suggest that you start over. With just those two service providers, you really don't need anything more than the simple, default, OBiTALK portal-based configuration. Keep in mind: if you make changes using the device's local web page interface, the portal will overwrite them, unless you disable using OBiTALK. So, you may have thought you made changes, only to have them reverted.
With regard to the DNS issue, your device isn't going to work with any service provider until you figure out what you've done wrong with the DNS setting. Keep things simple. Temporarily disable that parental control thing on your router. You cannot use opendns, and your OBi will fail to work if this is the case. Factory reset the OBi device with a paper clip. Delete it off of the portal and then add it back again using the **5 method. Don't make any custom changes at all (don't mess with digit maps and don't disable anything at this point in time).
Look at the Status page for the device, in Expert mode. The OBiTALK service must say "Normal". You can't configure Google Voice unless the OBi is at least communicating with OBiTALK. Look at the firmware version. What is it?
Configure Google Voice via the portal. You
cannot do this via the local interface, and you will not see your Google password on the local interface -- it is no longer used at all for Google Voice service. Make sure that you select the correct Google / Gmail account when setting up GV.
If this works, test inbound and outbound calling using GV. Does it work?