Mark,
I copied my real tracks and real drums to drive C with the rest of the program and all the problems went away. I suspect that some PC guardian type of software installed on my computer was interfering with file access through the IO ports

As long as I ran ANY of it from the USB, it took forever

I can't speak for you, but in my case everything I got from PGMusic was OK... the program, the real tracks, even the USB drive. Ultimately the culprit was my own system trying to protect me from myself.