Sorry if this has already been mentioned (I searched for "scrolling" and "scrolling speed" but didn't find any posts). Basically, the scrolling speed seems to randomly switch between reasonable and out of control-fast. It doesn't seem to matter whether I'm using the keyboard arrow keys or the mouse. There does not seem to be any particular event that triggers the switch, it seems to occur randomly. I just got the beta today, so haven't spent a lot of time with it yet (love it so far though). Perhaps I'm just accidentally hitting some key that triggers "fast" scrolling (i.e., could this be a feature that I'm just not using properly)?