This is what I did to get rid of it:
1. On the OBiTALK Device Configuration page, click to open the OBi expert
configuration setting.
Obitalk.com should ask you if you want to open the
expert settings, click OK.
2. On the OBi expert configuration menu, click "Enter OBi Expert"
3. In the Product information page, look for the "Voice services" menu,
(it should be located in the left side of the screen) click on it.
4. Click on "Auto Attendant" in the Voice services sub menu.
5. In the page, go to Auto Attendant 1 parameter and uncheck the Obitalk
setting case first, and then the enable case also, leave all the cases blank
and then click the submit button in the bottom of the page.
6. Go back to the Voice services menu and click on the SP1 Service (Or the one
your connected to)
7. On the SP1 Service page, Uncheck the OBitalk settings case of the
"X_Inboundcallroute" line and switch it to the default device case instead.
Then click the submit button in the bottom of the page.
This is what I did and I now receive calls without the Obi attendant greetings.