Okay, so I had a bunch of other stuff typed out, and then I found that their site has a domain checker, so you can see what the sites are tagged as.
So, I did a quick check.
Sadly, the site is currently categorized as Pornography. And actually, that's the only category that is currently approved for it. The other three (Chat, Adult Themes, Message Board), are all just awaiting votes at this point.
I'm not really sure there's much that can be done, really. OpenDNS has categorized the site based on a stereotype about the topic of a site, without really looking into it to see that it is a family-friendly site, and that the label isn't really warranted.
I see that on their site, there is a button to flag the site for review. It's possibly that the label could be removed. But you have to be a member to do that. And somehow I doubt that they would seriously review something that was flagged by one member who just joined, and who hasn't done anything else on their site at all before. It's a glimmer of hope that it could theoretically be changed...
The community reputation precedes us...