I really think you need to have a full consultation with a competent immigration attorney to discuss all aspects of your case. In terms of tax filings, I do not specialize in that area so you need to talk with a tax professional about how to amend your prior tax filings, if indeed, you made an inadvertent error on those. If you filed in good faith and fix any errors, you will not have a crime of moral turpitude because you will not have committed a fraudulent act. You should therefore be able to file for your naturalization, because all tax records will be fixed and there is no CMT. Then you can apply for your fiancee's case! Again, in your instance, DO NOT rely on my advice to file anything. Instead you really need to have a full consult with someone. Remember to breathe! From the facts below, it does not appear you will be barred from sponsoring your fiancee.
Answered on Apr 20th, 2011 at 10:24 AM