Heyo...

apparently this issue isn't just with Photoshop. I've done a little research and found out that certain drivers for Wacom Cintiqs and Intous have some tracking issues. It seems to create small angled lines instead of a continuous smooth curve. This looks fine when zoomed out but when you zoom in, it really shows especially on high resolution work. My Cintiq was showing the same issues as yours.

Right now I'm using driver version 6.3.6-3. works fine on my comp.

Cheerz