I dont know if everybody have done this but i was checkin something out and i had to restore my iphone, i had currently unlocked 1.1.1 with the anySim patch from the Dev Elite team. And when i downgraded to 1.0.2 all the call functions still worked! Even with the upgraded baseband.
So what i did:
1. Upgraded to 1.1.1
2. Installed anySim patch from elite dev team
3. DOwngraded to 1.0.2
And all the phone functions still worked...
Sorry if this is old news.
I used iNdependence for the downgraded/activation and jailbreaking