I'm not sure what's going on with your driver but I've used the heck out of mine for a year and have never had a problem with it.
You should contact Dave directly via e-mail. Also, you may get more information if you ask questions on the Yahoo Forum.
Since you haven't supplied any information about which board, power supply, motors, or general setup it's hard to make any educated guess as to the problem that you are experiencing. Are you sure that the chips are actually blown or is the problem with your computer, did you ever have the motors turning correctly?
I thought that I had killed my x-axis chip one time and switched to the a-axis but it still didn't work...I had a sinking feeling that all the chips had blown. Then I found out that I had caused the problem by installing a program to manage the files on my new cell phone that changed my printer port. I uninstalled the program and reset my computer to an earlier date. This brought my Pro board back to life.