I went back to the Mach 3 version that worked previously....still getting the same pulsing too fast error.

Looks like a PC issue.  Any thoughts on if the integrated video card is the cause of this or it is simply a difference in the newer parallel port.

Yes the on board video could well be the problem, if it is possible to put a video card in and disable the onboard in the BIOS it may work.
Hood