I asked that question myself a month or two ago. Never did get an answer. I've got 5.0 and there is a bug in that version where if you uncheck the "Auto Datum" (home) check box in the machine options, you have to change the start speed parameters or else you can't send files to the laser without the software crashing.
Maybe that is one of the bugs that are fixed in 5.1 but I don't know for sure. That's the only problem I've ran into with 5.0, other than the 2bit (black and white only) bitmaps. Sure would be nice if they came out with a version that would do 8bit grayscale like most other laser engravers.
Skip