Accidental Enhancement in IE

Sometimes, things happen in browsers that are just totally impossible to explain. Like this...

Ok, so that border on the feature object box is set to 1px dotted #D4E5FF. Now, we know that IE6 does not support dotted. But what the hell is it rendering here?

The craziest thing is that this weird multicolored border effect fits in with the colour scheme of the layout. It actually matches the colours of the background images! I have no idea what the fuck is going on, but it's the strangest thing I've seen in a while.

Interestingly enough, the effect disappears with a flash when the hover on the registration form link is activated.