I recently got a new drawing tablet (Monoprice Graphics Tablet) and i set up everything perfectly fine. However, i opened photoshop cs6 and when i draw, there would be an extra line. when i draw a semi circle, it automatically completes the gap with a straight line when i lift the pen up or stop drawing and it's really bothering me.
Here is a gif that i made to demonstrate what i mean: (click if it doesn't move)
also... my lines appear to be sort of jittery or non-smooth. even my mouse looks smoother than when i use my pen..
Check with the tablet maker for updated drivers.
The tablet may be picking up smaller movements that make it seem jittery, or may be sensitive to electromagnetic noise near the tablet (cables, speakers, etc.).