I agree with you gtSasha. It can be ridiculous. As my officer explained they are paying more attention now to people who owe money to the government. I can understand this move by looking at what happens to hospitals which can not get money for their services, unpaid tickets, unpaid tax returns by legal/illegal immigrants.
Actually my officer was kind enough to call me ONE DAY before the interview and asking to bring copies of checks I paid for tax return in the last three years. I am SO GLAD I had brought 5 years of tax returns with me. And since banks now have electronic copies of checks I had to call my bank and BEG them to email me copy of that check overnight and not within their standard 3 business days. Also I had to call IRS to fax me official letter I do not owe anything. And they faxed a letter, as requested, that I do not owe anything for last three years. But during the interview officer decided three years is not enough. I did not have copies of other checks but had bank statement with exact amount that was paid to IRS that match my tax return amount. And it DID NOT work, because officer said this is not a proof you paid IRS, you may paid for something else. You know what worked? In some tax returns I underpaid during the year and in another I overpaid. So he figured that I and Gov are even.
The whole experience was pretty frustrating. My wife had interview with another officer and at the end he said her case is pending due to missing info. We waited ONE YEAR after the interview and when she get to the INS to discuss what is going on another officer said "oh, here is your file. We just put it in a wrong place. And there is nothing wrong with it. The officer who interviewed you was intern and did not know what to do".
If I'd have to go through this again I'd hire a lawyer.