Ok I've been a resident since 2003. I have filed my taxes regularly until 2006. In that year I didnt work or make any money so I didnt file my tax return. 2007 was the same however in 2008 I started working again and filed my taxes for that year and also the last year. I just sent my N400 application in, and today I received a letter saying they received the payment and they will send me a date for FP and Interview upon all the records check out OK. Do you think the years I didnt file my tax returns would cause a problem? When I asked an IRS agent he said, they dont have any records of me making money in those years so IRS is ok with this situation and they said I dont need to file them right now or ever. Do you think its ok with immigration also? or is this a red flag that I should take care of right now.