Hi, there are two types of Lock Stage... one is the PIN, and the other is the Subsidy Unlock... as with the PIN, the Main PIN 1 for Cingular is 1111 and SIM PIN 2 is 2222, if you enter three times of wrong PIN then the Pin will be BLOCKED, once it is BLOCKED, only Congular Customer Care will be able to unlock them and all you need to do is to enter the New Pin. If this carries too much (5 Times) of unblock, the SIM will consider as "{Burned)", and the Word "Burn", it can have two matters... 1) Carrier Burned the Card for you, e.g. Sim Card Change, Account Closed, and/or Sim Card Stolen, this will actually not be able to do the "CPR", the SIM is consider as "Dead". As with the Phone, there are always a Sibsidy Lock for the carriers, if the Subsidy lock enter 10 times mistakes, then it will "Burn the Phone" and "The SIM", which the Manufacturer will have to "SCRAP" the phone, and the SIM can be put it in your Home Museum for the SIM Card History Personal Records.
Hope this Helps...
P.S. When I said "Burn" it does not mean "Smokes" or "Electric Lighting", it is just a term for "Dead"!
Good Luck!
ACKuo