well if its possible for you... you might want to try relocking and then unlocking the phone from an xp computer and see if that changes anything. im trying to remember how i did mine, and i think i ended up using my laptop because using xp was easier
and use this thead for unlocking
http://forum.ppcgeeks.com/showthread.php?t=35839
i think its possible you might have unlocked using the soft spl unlocker. which, i think, is not a permanent unlocker. ive never used an sspl so i dont know. but i do know that you want to unlock your phone with an hpsl- hard spl unlocker