[craig96us]

I will check the diodes as you described. I am at work right now, so I can't fiddle with the machine until later this evening.
I found the post that you pasted in yesterday evening while I was searching for more information that might help me fix this thing! After single stepping the axis, and not seeing the backstep, I decided that I should post my problem and see if anyone could help.
Your description in that post, and obvious knowledge of the inner workings of the stepper drive circuits is what prompted me to post my problem here! Thank you very much for being willing to help and share!
Based on what I read here, I now know that I may have a diode problem, and replacing the transistors could be an exercise in futility. I will have to determine if the diodes, or the transistors are at fault before I start shotgunning parts...

I will post what I find!

Just for fun, I am attaching a photo that my wife took of me working on interfacing my laptop with the BOSS6 so I could transfer gcode programs etc...