I'm in the same situation you're in. I've had my work authorization but didn't receive any info from immigration regarding my case for almost a year. I called FBI and they told me, that my name check was clear and they sent my information back to Immigration almost a year ago, I guess before the interview, then I had to wait for a year, got tired of this uncertainty, called them again, they forwarded my request to check my case, then I received a letter which said, that they couldn't make decision on my case until my background check was completed. I believe it's not true. Background check is done either by CIA or FBI, when they check whether you're a terrorist, communist, spy, etc. or not. They say it may take years. Name check, I think, is when they check whether you are who you say you are, or something like that, I guess. Good luck to you.I received a phone call from congressmen's office in the month of June 08 that my name check was clear. I had initiated service request on Aug 08 and received a letter from USCIS today saying that the background check is not yet clear.
Please advice if congressman office was wrong in giving information that the name check was unclear.