have you tried black rain or redsnow yet, has it got the updated firmware?, when i did mine i had absoloutly no problems tbh was literally plug and play so something isn't right (obviously ), plus that new jailbreak wont unlock it i don't think to any network just jailbreaks the software, when it's connected to itunes does it ask to update the phone or does it state it's got the latest software installed on the iphone screen in itunes, worse case update the software and try again.