I am currently working on getting the factory sounds back onto an M1 that had a dead battery. I replaced the battery and there were no sounds at all as I expected since the memory got wiped. I don't have a fancy midi adapter only one of the cheap $10 midi adapters off of ebay. I tried using the factory preload library from korgs website and have been able to get one horribly out of tune sounding piano sound to play after transfering the M1preld.syx file I tried messing with the transfer speed/buffer on my laptop, but that did not seem to do anything.
I had read on some forums that using the cheapest midi for sale online could be part of the problem so I have been looking around to see if a slightly more expensive used one would get the job done. I was looking at either a Roland Edirol UM-1 or a roland Edirol UA-25.
I'm not 100% that the cheap adapter is to blame and it could be something to do with my settings in MIDI SysEx transfer utility or Bome SendSX. I have used the cheap ebay adapter in the past to restore the settings to a Roland D-50 and is the reason I have the thing in the first place, but don't mind buying a more expensive one if I need to.