Dear Everybody: i'm not really sure what you've tried, but i'm an adoptee from california and i found my birth mother in korea. it is VERY possible to find your parents even if you are an international adoptee.
i would suggest going through your own adoption agency and getting information like your adoption/case number. if you were adopted through HOLT international, you can request things like a search, or even files that they have on you. i found that they had a lot more in my file than in the one that they had given my family.
if you are a korean american adoptee, asides from contacting HOLT, i would also contact GOAL (global overseas adoptee link).
http://goal.or.kr/new/
good luck to you all.
blasfemme