trademarks

[imsnookboy]

I recently started a web-site, bought the domain name, incorporated my company using the web-site as the name and registered my web site for copyright.  Now, I've been contacted by someone saying that they own all derivatives of my company's name and they want me to cease and desist.  I thought I took all the right precautions.  I feel like I'm being bullied, as this guy is by now means known nationally and the web-site's name is not a household word.  Do I have a leg to stand on?