See if you tried it this way. http://www.technonix.com/2009/11/unlock-and-jailbreak-iphone-3-1-2-baseband-05-11-07-using-blacksn0w-or-blacksnow/ and here is the forum for people that have a hard time with their carrier etc. may be this is something that pertains to your situation http://modmyi.com/forums/t-mobile/325421-help-no-service.html
and http://www.sinfuliphone.com/showthread.php?t=14656