What is going on here? I got it today and after 7 hours i did a firmware update from v2.0 to v2.2 and now i have a useless LP with sx code error 2 and that trick with the master button on boot isn’t working. I had in my mind that these fw problems are “rare” but my worst fears became real! Please! Don’t tell me that i’ll have to find a debugger and open it etc…!!!
Everything is ok! What a relief! I tried again to send the fw through my card’s (emu 1212m) midi interface with midiox (not through usb) and it worked fine!!!
It was the worst experience i had with equipment! Back to pure joy! Little Phatty is a little miracle (except the firmware upgrading procedure and its knobs…they are not so sturdy compared to a Voyager..)
USB is pretty useless for reliable MIDI.
I learned this the hard way with the DSI Tetra, it’s editor can’t even write patches through USB at the moment. 
As it seems usb is only good at controlling virtual devices for the moment..