Hmm I'm not fully brushed up on the rules for american .COM domains but the first thing to do is run a WHOIS test on your domain and see who is listed as the owner. If there's no mention of your name and only the hosting company is listed then you might have a problem, but usually you can prove your ownership by using other evidence.
The key is to find out who is the primary registra for your domain and InterNIC might be able to help. http://www.internic.net/index.html