I'm using Photoshop CC 2015 on my Surface Pro 3, and the pen controls are wonky somehow. I wish to write/draw with my pen, but it only works when I stroke sideways. But when I stroke vertically, it attempts to pan/scroll through the screen instead. I'm having this problem for every tool, including brush, eraser, zoom, marquee, etc. Whatever I'm using, it only works when I stroke sideways, and just moves the screen when I stroke vertically. Is there a setting that I need to change to make this work again? Please help.