Why can't a decision be made yet about naturalization application?

It is difficult to determine what the problem may be without reviewing the application. Delays in naturalization decisions are usually the result of prior arrests/convictions, failure to file in one tax returns, questions about whether you were properly granted residence, or completion of background checks. USCIS has 120 days to make a decision or otherwise request documents/re-interview. If USCIS does not act within 120 days, you may request the U.S. District Court consider your request for naturalization. You can read more about naturalization at http://myattorneyusa.com/citizenship-and-naturalization.