I have to use a pencil simulating brush just to "hide" the messy lines.

Sample of my using the Normal hard brush can be found below. Notice the terribly bumpy lines. Even in a simple arch. The slower I go, the bumpier it gets (last 3).

I've managed to find a copy of the tablet software on the internet and installed it.
I've tried all sorts of settings and none seem to fix the issue nor come close.
I'm trying to get this set up correctly b/c my friend said she may let me keep it. ^_^
It's not a big tablet. It's a old Wacom Sapphire from 1995 or 96. And only has a 3.5x5 inch work space.

Is there any help either of you (or others) can provide?
Thanks