My home number was ported to GV a couple years back and I have been using OBI ever since.
Many months ago I was playing with apps such as GrooveIP on my smartphone, to use my other GV number on my cell - but the quality just wasn't working well - so I stopped messing with it for nearly a year. I recently started tinkering with it; and I've had pretty good success at using the APP to make GV calls from my smarthphone, and thereby not use my AT&T minutes.
However; when I use the GV APP on my cell to call my home number, which is a GV on OBI; it immediately goes to a voice mail. What's even weirder; if I call my house using my normal cell provider AT&T, or my work phone I call my house, a different answering machine picks up.
My standard answering machine messages greets people with a company name (wife's home business), but when I call with my GV app on my smart phone, it greets people with a "thanks for calling Joe, please leave a message" - and the home phone doesn't ring and in call history on OBI there was no incoming call showing.
It feels like it might be a GV setting on either my house GV or cell GV - but not getting it. It doesn't seem to be the OBI Attendant either, because it's my voice answering.
Looks like you are calling yourself on that GV number. In that case it will go straight to your VM. I imagine that GrooveIP is registered with your (same) GTalk account.
That was a great thing to check, but no dice.
I have two Google accounts - Google1 for home, and Google2 for cell, so two different ID's. My GrooveIP APP is using Google2 account, and at home the account GV uses on OBI is using Google1 account.
Further investigation shows that on my home GV account, under Settings > Voicemail & Text - there is a Voicemail Greeting and next line is Recorded Name.
When I call from my GV2 to GV1, the Recorded Name message plays right away - not the GV1 Voicemail greeting.