Do you have Parallels installed? I corresponded with the mfr in Italy when I had a similar problem, and this is what I was told:
"Hello Jay,
by the log you sent us, my programmer has seen you're running parallel. It may be that it's sharing resources with the native OS, i.e. the USB. This could lead to problem. Can you try using hiFace after killing parallel?
Marco"
Removing Parallels from the disk from which I run the hiFace solved the problem for me. Good luck. Cordially,