When was the out of status, was it before 1998 (before the so called new immigration law taken into effect)? When was the filing of immigration petition? Which type? before April 2001 (ends of LIFE 245i extension)?
Also, most important, what was the basis of your eligiblity? US citizen's spouse, EB,...?
It will also affect who should file the appeal, you, employer, or one other petitioner. Wrong person filing I290B (such as you filed for I-140 apppeal or company filed for 485 appeal) will get FAST rejection by AAO. Because AAO doesn't even need to look into the material facts in these cases.