Just came back from Congressman office and got the above information. My NC was completed in August 2007, still haven't had the I-485 adjudicated. I was told that once NC was completed by FBI, the result was generally back to Service Center. However recently some cases (three more besides mine) were back to DC center instead of Service Center. I asked the lady if this was meaning that FBI found some problem on those people. Since this was the first time this Congressman office got such kind of reply, she doesn't really know what this means. Anybody had/has similar situation?
I also called TSC a lot of times, was never told this kind of reason. In the last call, I was told that everything was fine for my case but just hadn't yet assigned an IO. She was going to email the officer and asked me to wait for 60 days.
I think having waited for 2.5 years is not common for EB1. Really frustrated. Every step (I mean from J1 waiver to GC) was hard for me since coming to US.