XPS 15z trackpad/touchpad problems. I'm at my wits end.

Good lord, I've had nothing but problems with the trackpad since I bought this laptop.  At first it was just terrible drivers.  I thought I had everything solved by using the XPS 13 drivers, and setting the following registry entries to 0: DisableTrackPadWhenKeyboardActive KeystrokeDesensitivityEnable

Everything seemed solved and worked the way I wanted it to.....for about a week.

This evening I came home from work, and the touchpad is unusable.  If I drag my finger across it, the mouse pointer is slightly delayed in moving across the screen.  Then, once I get the pointer where I want it, if I lift my finger off the touch pad, the pointer jumps an inch in a random direction.  It's like a cruel joke.

I have tap-to-click turned off.  I've tried to uninstall and reinstall the driver.  Previously, when I hated the driver that came with the laptop, I was able to uninstall it and use the default Windows 7 driver fairly well, the one thing I couldn't do was disable tap-to-click.  That's when I found the XPS 13 driver worked the way I wanted.  But now nothing I do helps.

Here's another symptom.  If I attempt to use the vertical edge scrolling while the cursor is in the textarea for this post, it actually outputs letters into the textarea.  So if I scroll up right now it produces this: bgbkmnpepppqdplke

I have no idea what's going on.  Whoever heard of vertical scrolling actually typing letters?

I've run Malwarebytes Anti-Malware and my anti-virus software and found nothing. 

This is truly frustrating.