Hi, sarwarmd.
My case was a little complicated. After the successful interview, I was waiting for the same-day auth ceremony at Baltimore DO. Suddenly, the officer who interviewed me came out in pale blue to bring me back to his office, and said that my application was, in fact, not eligible because mine didn't meet 3-3-3 rule by nine days. To be eligible for citizenship via spousal citizenship, you must be a permanent resident for three years, you must be married for three years, and your spouse must have been a citizen for three years prior to submitting an N-400 application. I had been a permanent resident for three years (-90 days grade period), I have been married more than 10 years, but my wife was 9 days short from 3 years since she became a citizen when I submitted my N-400. No one ever noticed that until the moment I was waiting for my auth ceremony, including myself, the initial screening officer at Texas center, and the interviewing officer at Baltimore DO.
The officer basically rushed me to write a voluntary request for withdrawal of my case, since it was obviously the fault of the USCIS by processing my application without checking the eligibility (usually this kind of ineligible application should have been returned after the initial screening), and the case was already approved at the moment. All they wanted was to avoid the trouble. According to my friend who's the district office director of USCIS at another city, I could have appealed for the approval based on the error from USCIS. However, I also didn't want trouble with these people. So, I wrote the request letter as the officer wished for. The case was withdrawn. I had to submit mine again. No fee was waived. Had to fingerprint again. No preference was given for re-interview. Just double the time, double the money.
From what I have experienced, you might want to calculate your estimated interview scheduling date from your priority date, not from your fingerprinting date. Some people do fingerprinting early with walkin, but they don't necessarily get their interview scheduled earlier than others. It appears that DO ques all applications based on their priority dates before they are scheduled an interview.
