fyan,
i suggest you let a lawyer file your AOS through marriage to USC.
also, read this and you'll feel better after, i know i did
i got this in this link: (please note the clause highlighted in red)
http://www.uscis.gov/graphics/howdoi/LPReligibility.htm
Ineligible
There may be other reasons that you are eligible for adjustment to permanent resident status. Please see USCIS Form I-485 for more complete information.
You may be ineligible for adjustment to permanent resident status if:
You entered the U.S. while you were in transit to another country without obtaining a visa.
You entered the U.S. while you were a nonimmigrant crewman.
You were not admitted or paroled into the United States after being inspected by a U.S. Immigration inspector.
You are employed in the United States without USCIS authorization or you are no longer legally in the country (except through no fault of your own or for some technical reason). This rule does not apply to you if:
You are the immediate relative of a U.S. citizen (parent, spouse, or unmarried child under 21 years old).
Certain foreign medical graduates, international organization employees and family members.
You are a J-1 or J-2 exchange visitor who must comply with the two-year foreign residence requirement, and you have not met or been granted a waiver for this requirement.
You have an A (diplomatic status), E (treaty trader or investor), or G (representative to international organization) nonimmigrant status, or have an occupation that would allow you have this status. This rule will not apply to you if you complete USCIS Form I-508 (I-508F for French nationals) to waive diplomatic rights, privileges and immunities. If you are an A or G nonimmigrant, you must also submit USCIS Form I-566.
You were admitted to Guam as a visitor under the Guam Visa Waiver Program. (This does not apply to immediate relatives.)
You were admitted into the United States as a visitor under the Visa Waiver Program. (This rule does not apply to you if you are the immediate relative of a U.S. citizen (parent, spouse, or unmarried child under 21).)
You are already a conditional permanent resident.
You were admitted as a K-1 fiancé but did not marry the U.S. citizen who filed the petition for you. Or, you were admitted as the K-2 child of a fiancé and your parent did not marry the U.S. citizen who filed the petition for you.