I'm not sure if this has any relevance to your problem, but I figured I'd give it a shot?
When I first started out in '97, I bought a GRC-60 and V.E. Master software. I was running it on a PowerMac 7300. I decided to upgrade my computer to a Mac G4 a few years later, and figured I wouldn't have any real problem with the switch? Boy was I wrong!
I ended up having to get this thing called a Keyspan adapter, and have to use that to use my old software with my newer computer. I've got a hardware dongle coming out of my Mac G4 keyboard, that Keyspan adapter coming out of the back of the computer itself, and finally I ended up having to use some serial cable off of another cutter I had to get my Summa T-Series to run with the setup, instead of just being able to use the USB that came with it? I've got a fancy cutter that is fairly new, a computer that is getting pretty close to being outdated, and software from the previous century! It is a complete Frankenstein setup, but it keeps on working for whatever reason? (Knock on wood!). Let me know if you find the solution to your problem, because it does sound a little like the problem I had when I switched to a newer computer / operating system? Look into that Keyspan adapter. Good luck!