What happens to my I-485 case? Please help me!

Dear XDJM, please give me a hand on my case. Here is the information of my case:

I-140 Submitted: May 2005
I-140 Approved: June 2005
I485 Submitted: August 2005
Finger Print: October 2005
Category: NIW, TX Service Center

After October 2005, I did not receive anything from USCIS. I requested my case status last month. I received a mail yesterday, and it says that my status is “outside processing time”. Following statement really confused me:

You need to schedule a biometric appointment through www.infopass.gov or call 1-800-375-5283. Please make sure you select the following option: You have received an approval letter or form I-797C from the service center or local office instructing you to come into the office for alien identification card processing/passport stamp. The alien resident registration card can’t be produced until the biometrics has been completed.

I sincerely hope XDJM here can help me to find out what happened to my case:

1. Why needs biometric appointment again? I had that last October.
2. I did not receive an approval letter or form I-797C. Does it mean that I need to wait for it before I make an appointment?
3. What’s the meaning of “outside processing time”? Does it imply that my name check has passed?
4. Does this letter imply that my I-485 has been approved, but I need to wait for the priority date to be current?

A lot of thanks!!