I am posting my experience right after coming back from Houston.
Hope it will be helpful for you.
We are assigned to the ASC in Houston Northwest.
As soon as we went , the person at the door saw the letter and said the approval notice is not enough and we need to show the appointment letter from USCIS showing the time and date .
I told him that we do not get appointment letters as I have called TSC and were told that no appointment letters will be sent. But we have confirmation numbers.
I insisted that he read what the approval notice says about taking to the appointment. Just the notice and photo ID. I also showed him my firs fingerprints letter (biometrics code 3) completed on August 5, 2005. At that point he told me to go and speak to the supervisor.
The supervisor looked at the letters (approval notice and fingerprints notice from August). I told her that I have conformation numbers. She told me that she does not need them. She wrote code 2 on the approval notices and told me to go and get the paperwork done.
They took picture, fingerprint (right index finger) and signature.
Guys, if you are going for the biometrics and the door fellows ask for appointment letters, do not turn and go away. Show the door men the previous fingerprints letter.
Insist on speaking to supervisors.
I wish all of you good luck and hope you will be able to complete your biometrics with out any problem.
Some details of my case
I-140 RD August 16, 2003 (EB-1b: outstanding professor/researcher)
RD August16, 2003
PD August 18, 2003
I 140 AD August 9, 2004
I-485 RD April 6, 2005
I-485 AD August 16, 2005 (strange approval notice)
FP ND (code 3) June 21, 2005
Biometrics done August 5, 2005
EAD ND August 10, 2005
EAD AD August 16, 2005
LUD 8/05/05, 08/08/05, 0811/05, 08/16/05, 08/17/05