Hi Alec,
Did you have to use the JTAG socket as well? Yes it was a little daunting at first, but with the easy to follow instructions in the pdf file Murray sent, and a little common sense working out how to do this via the 10 pin JTAG socket rather than the 6 pin ISP socket, it was relatively painless. It also helps to have the correct tools. :) I had first tried with a cheaper programmer but then found out it wasn't compatible, so I then bought the Atmel-Ice Debugger Full Kit, and although not cheap it was worth the extra cost, plus I can now use that for some other projects.
Thanks for the useful tip for those who dont want solder the pin header, to instead twist the header connector to the pin header in order to obtain good contact. I had also noticed the pin headers on my Kiwisix were pretty loose but I ended up just soldering them to the Kiwisix board.
And finally those MidiOx settings worked beautifully. I tried a "Dry Run" first, sending the Kiwisix firmware files through MidiOx without the Midi Out cable connected. I have had that MidiOX buffer depletion happen in the past when sending a large sysex file, so those sysex config settings are worth remembering. :)
Thanks again and cheers for now
Tim