Basically it seemed that I had corrupted the Kiwisix bootloader somehow, so Murray sent me a file and some instructions. But because I have an earlier version of the Kiwisix PCB which only has the 10 Pin FACTORY connector slot, so I had to make some slight adjustments to the process. After trying a couple of cheaper programmers which didnt work for me, I eventually had success using the Atmel-Ice Debugger (the Full Kit version was required as it has the adapter with correct connectors.)

So after reprogramming the Kiwisix board, I did a Factory Reset, then successfully updated to the latest Kiwisix firmware, so a big thank you Alec for those Midi Ox settings, they worked a treat. 

Although it was somewhat frustrating when it first happened, this has actually been quite an interesting exercise, even if unintended, haha. Anyway, now I need to go and update my Kiwi-3P to the latest firmware, but hopefully that will go through ok with those MidiOx settings.

Thanks again everyone, much appreciated, and if anyone else has this happen to them, let me know in case I can help with some of the more finicky aspects, now I know what to do :)

Cheers

Tim