Are Taxes from last year not filed yet considered overdue ?

You are normally allowed until April 15th to file last year's taxes or to request an extension of time to file. Although I am not an accountant, you would not appear to me to be delinquent on your taxes at the present time and your answer would likely be "no". If you file your N-400 naturalization application before April 15th, it would appear to me that a "no" answer is proper. The intent of the naturalization form’s general questions is to determine good moral character, and it would not seem that U.S.C.I.S. is intent upon learning about persons who have not paid advances on taxes as much as it is interested in persons who have clearly violated the tax codes. Due to the limitations of the Lawyers.com Forums, Alan Lee, Esq.'s (the "Firm") participation in responding to questions posted herein does not constitute legal advice, nor legal representation of the person or entity posting a question. No Attorney/Client relationship is or shall be construed to be created hereby. The information provided herein by the Firm is general, and requires that the poster obtain specific legal advice from an attorney. The poster shall not rely upon the information provided herein as legal advice nor as the basis for making any decisions of legal consequence.

You should include a letter from your tax preparer (get one if you don't already have one) with a citation to and copy of the IRS regulation that allows you to file at a different time.  The bottom line is that your taxes are not overdue if in your situation the law doesn't require you to file a return on April 15th.