http://hackint0sh.org/forum/showthread.php?t=15849
In FAQ:
Q) My iPhone wont work with (name)simcard! Whats going on?!
A)
If you can read, this guide does not tell you how to
UNLOCK your iPhone. It allows you to jailbreak & pass activation. Therefore, a UK iPhone running 1.1.2 will
only work on O2 simcards, a DE iPhone running 1.1.2 will only work on T-Mobile, and so on..