I think I've figured it out. If the 'Memo' field is blank on the main screen (and I specifically mean the 'Memo' field on the main screen; the 'Memo' field on the popup screen seems not to be a factor) and you create a MIDI file, that MIDI will be corrupt and crash PTP w/an 'Error: 230'. The Windoze Media Player will lockup and who knows what other programs will do. I've reproduced this several times now so I'm sure this is the problem. Others might try reproducing it as well. It seems to me that this is a BUG, and a pretty well obscure one too.