Need a solution for naturalization issue.

My friend filed an application for CSS amnesty case and got A # on that application. My friend was scheduled for Work Permit Interview, did not get work permit and was asked to bring some documents. After this interview, no further action was taken on this application either by the applicant or by INS at all. Two years later my friend got DV Visa Lottery. The lawyer helped and the whole process went smoothly. My friend got green card without any problem. After another 2/3 years my friend came to know that the application filed early for CSS amnesty was not mentioned/disclosed in the DV VISA application/documents by the applicant/lawyer and the green card has another/new A #. Now my friend want to apply for citizenship But afraid that INS may find out old application and deny citizenship or any other problem. What my friend can do to get citizenship without any problem. Please help with real legal advice / Solution. Thanks