X.O.
Are you retaining an attorney to represent you at closing? Since the legality of the check is in question, I'd consult a real estate attorney. Our atty fees for our recent purchase was $500. If you just have a simple question that can be easily resolved it should be quite affordable to have answered.
Another idea - www.Trulia.com is a great resource for both house listings AND even better, professional advice from local real estate agents. Perhaps you can post your question for the professionals in your area to answer. I got a TON of great answers to my questions when I posted there.