What is the SIM card default unlock for a Cingular SIM card in the usa?

That is, I've unlocked the subsidy from the Motorola cell phone but now I
can't use the original Cingular SIM card in any phone? What did I do wrong?

Here's what happened:
1. I called ATT/Cingular and requested a "subsidy unlock code" which was
emailed to me a day later (see email below).

2. The ATT/Cingular instructions said I had to put a non-Cingular SIM card
in so I put in a T-Mobile SIM card (which was working fine in another
phone).

3. So, I popped the non-ATT/Cingular SIM card in the Motorola RAZR and the
Motorola RAZR asked for the 8-digit subsidy unlock code which I entered and
hit OK and it said it was unlocked. I made a phone call using the T-Mobile
SIM card to prove the subsidy unlock worked.

4. HOWEVER, when I put the original working Cingular SIM card back into the
Motorola phone, it then kept saying "Enter Unlock Code" where it expects 4
digits. I tried 0000, 1245, 5678, 0123, 9999, 6666, etc (every combination
I can think of) but I can't get past this Cingular SIM card unlock (which
isn't the subsidy unlock).

5. In fact, when I put ANY SIM cards (T-Mobile or Cingular/ATT) into the
now-unlocked Motorola cell phone, it says "Enter Unlock Code" and then when
I enter "0000" and hit "OK" it says "Unlock Code Incorrect. Try Again".

It must be in the phone 'cuz the SIM cards work find in a spare phone. What
is the default unlock for the Motorola RAZR if it is not what I tried
above?

WHAT is going on?

WHAT IS THE DEFAULT SIM CARD UNLOCK if it isn't the ones I tried above?

catherine

HERE IS THE EMAIL FROM ATT/CINGULAR (modified to obfuscate the code
itself):

Your subsidy unlock request was received and processed, see below for
details:

IMEI #: ###############
Unlock Code: ########

(To verify IMEI # press *#06#, this will poppulate a 15 digit # on the
screen. If this sequence does not work, simply pull the back and
battery out of phone and the IMEI will be listed on the back of the
phone under the battery.)

Caution: If this process is unsuccessful five times in a row, the phone
will be permanently locked to the new at&t network. Do not attempt to
enter the code more than one (1) time total. Instructions below will
assist you in unlocking your device, if these steps are unsuccessful
please contact us at 1-800-331-0500 or (916) 843-4685 from overseas.

Motorola
Subsidy Unlock Process
With non-Cingular SIM inserted in device
1. Turn on handset
2. Enter unlock code when prompted
3. Press OK
4. Device should now be unlocked.