The scrollbar isn't present for the left pane when using Chrome. It's there in Internet Explorer and Firefox. Haven't tested others. I can scroll down the list by highlighting the icons and dragging off the window, which is obviously pretty wonky.
I almost posted on this the other day, however I noticed that when I clicked (or pointed) into that frame and used the scroll wheel on my mouse, the menu scrolled for me. I was also able scroll with the arrow keys. I'm not sure if the scrollbar is missing due to a bug or due to aesthetic reasons.