The brush and pencil make a straight line down across drawing area. Updated Flash CC and tablet driver. My computer is a HP I7 desktop running Windows 7. Just got this new tablet on line and other drawing programs do work.
Solved my own problem. I run Flash as administrator and it did some updates and now it works. I right clicked on the Flash desktop icon and run as admin.
Thanks for posting after you fixed it. That helped me fix it as well.