According to a moderator on CNET’s forums, MapVisitors does not work with Seamonkey and AdBlockPlus, see thread –

http://forums.cnet.com/5208-6616_102-0.html?forumID=37&threadID=232312&messageID=2396273

I’m not sure what Seamonkey is but I’d bet is a flavor of Mozilla or built off the Mozilla code base? Yes apparently so http://www.mozilla.org/projects/seamonkey/ – it is essentially Firefox 2 and Thunderbird 2 with some security thrown in. It sounds like a good idea however despite many cool features (advanced security settings, cookie and password managers, the latest in web standards) we can’t recommend Seamonkey until they fix their application to work with our web site. Also, it appears they use Composer instead of NVU.