I personally downgraded 1.1.1 to 1.0.2 and tried couple of methods to flash the baseband none of them seems working. We should wait for the dev team for a solution to this, since as fas as find out with another iphone 1.0.2 there is a limit to flash the baseband and when it exceeds you can not unlock your phone.
Mr personal opinion is that, downgrading to 1.0.2 is a big step (remember magic firmware 1.5 of psp) after this DevTeam may find a solution for us.