I upgraded from Ubuntu 12.10 to 13.04, and I've noticed something is not working properly. In 12.10 it was easy to slide up and down the vertically-inclined sidebar by simply rolling the mouse wheel up and down. This feature was pretty minor but much appreciated. I recently upgraded to Raring only to find that this glorious feature is not working.
My question is how do I re-enable this mouse wheel scrolling along the Ubuntu sidebar? Surely there is a way to re-enable this. It's such a simple thing; it's just the way the sidebar responds (or chooses not to) a piece of hardware telling it what to do.