Seems the page is broken. All the board turn to blank after a while. http://online-go.com/observe-games
same happen here, if you leave observed page at background and return to it later all boards are ‘wood’, no borders or stones.
Indeed, seems to happen very reliably when toggling between the rank and speed sorting. Wonder when I broke that…
It seems old games are not purged from the screen. I start with 9 games and after a while I have more and more. It’s nice that they are not purged immeaditly but maybe they could fade away slowly?-)