Every so often this happens on my computer too, I'm using Google Chrome, all the icons enlarge themselves and so become pixelated. At the same time, the icons seem to lose their fixed location and fall behind any text that happens to be nearby.
I would like to hear a staff response on this issue.
I've noticed that, every since the beginning of 2009, many images, such as the chess.com logo, some pieces on the front page, pieces in Tactics Trainer, smiley faces, the spell check icon, and other images look like blurry jpegs! Why is this? I use the latest edition of Firefox 3.