Well you can add meta words on your site. That way they'd know what to search for. The problem you're having may have to do with your host. If you chose a free host your site may be registered on the same IP address with a few other websites, instead of each getting it's own. Now if you were to pay for a host you will usually get your own. The google bots will be viewing the page as
www.267.3265.125.com (sample ip probably not even the correct numbers per area but its an example) not as
www.yoursite.com. This will cause it to put there keywords onto yours as well, and maybe the other sites are getting your keywords. It's a complicated problem I read about a while ago. What host are you using, and is it free?