The ornamental design at the far right of the screen covers much of the scroll bar for the chat. I'd not noticed this before, but today I wanted to scroll back to see how many games I'd played. My first impression was that there wasn't a scroll bar, but then I noticed bits of grey peeking out from behind the ornamental design.
I should clarify that this happens on the web page that shows the result of the game, not on the web page on which the game is played.
Thanks for the report, I'll look at that.