I have a similar issue with the Calvin Klein ad. However it has not appeared once while observing games. It would literally freeze the game I am playing or force a server abort for a game I can't play.
I have lost several games on time due to this ad.
It does not move or have animated text. Something about this ad causes the live chess server to freeze.
In Live Chess, every time the Calvin Klein ad appears, the website hangs up. In Google Chrome, I see messages in the lower left corner, saying things like "Processing request...", "Waiting for livechess...", "Waiting for ad.doubleclick.com (or some similar URL)" briefly appearing, over and over in quick succession.
I see this every time when observing games -- I rarely play, I just observe. You guys probably don't notice because you're focused on the game you're playing.
I've notice some people saying they're getting disconnected in the middle of their games... I suspect this has something to do with it.