I think I remember seeing someplace that you can't run VM and Mach on the same computer. Is that correct?

You can run anything you want on a PC with Mach on it. You just shouldn't run anything else while the machine is running. Although it VM has a dongle, you don't want to run Mach3 through the dongle. Put any dongles on a printer switch box and switch over to it to run the software.

Oh right, I forgot the dongle. Thats probably what the issue was with both on the same computer.

Well, I happen to have an add-on parallel port card sitting around - the dongle probably wants LPT1 but I can switch Mach to the second port.

Thanks!

..or exchange your parallel port VM dongle for a USB one. Unfotunately not free, though, they want about $100 for that... --ch