_constrainPanCoords doesn't currently take in to account the zoom factor which means we overly constrain how far we can pan, which makes panning while zoomed quite painful.
Created attachment 338488 [details] [diff] [review] patch This makes sure we only pass page coords to constrainPanCoords, and includes some other simplifications. Kinetic is really broken with this, though, since it compares dragX/Y and pageX/Y which are screen coordinates and content (page) coordinates, respectively. I tried figuring out what the kinetic code is trying to do, but I didn't end up getting anywhere - I've just disabled it for now.
verified with beta3