[BobbyH]

You likely ran afoul of "voter ring detection": http://twitter.com/#!/paulg/status/22551773068

I think it works something like this. Say you and I are buddies and only upvote each other's articles. The voting ring algorithm thus flags us both as being part of a voting ring. Votes on our articles are then penalized by some amount to reverse this gaming. Detecting voter rings is important as failing to do so has really hurt communities like Digg.

On a related note, if most of the votes on your articles comes from readers on your site that only upvote your articles, those users will probably all be flagged as part of a voting ring.

[mvandemar]

It's pretty rare that my site shows up here, and my actual readership isn't huge, so I don't think that is the case. Any way to find out though?