Aganju: has no effect on the game itself (aside from that you cannot see how many pieces are stacked up).

Heh heh. That's quite a large effect! ;o)

At this move, the standard backgammon images, such as http://i.brainking.com/back/bpuup40-13.gif, show up but the capture image (http://i.brainking.com/back/wreup40h-2.gif) gives a 404 Not Found error.

That's the size-40 image set and it's clearly missing these Plakota images. In the smaller size-25 image set they are available. http://i.brainking.com/back/wreup25h-2.gif.

It's definitely a bug.