EuDemons Advertisement

I've recently started experiencing major intermittant browser-slowness and stalling when using chess.com.  In some cases when I pick up pieces on turn-based, they are not removed from the squares that I picked them up from (causing them to be appear to be duplicated -- which does not effect the back end game but does effect the presentation).  I've tracked it down to a specific advertisment which causes it -- the EuDemons banner at the top.

I'm curious if anyone else has this problem or if it's just manifesting in my environment -- Firefox 3.0.13 on Ubuntu 9.04

It's very frustrating when this ad comes up ( which seems to be at least 50% of page loads ), as I specifically remove this site from my global ad-block list because I like to support it.