Apparently it is not actually scanning the site (?), but any link to the site.
For example, if you Google "windsun forum", our forum is the first two links. If you have AVG and right click on any of those links to the forum, you get the message. In fact I can click on the link in my first message here and get the same warning.
If you have Linkscanner or the new AVG 8.0 with Linkscanner built in you can right-click links to check for "bad sites".
http://store.yahoo.com/lib/wind-sun/img2.jpg is the popup I get.
If you do the same for a link to
http://www.wind-sun.com/ (not the forum) you get the same warning, so it appears to be site wide, not just the forum - but the forum is about the only thing active there right now.