Sorry to disappoint you, Snuffy! I produced that file in Cakewalk with only a mouse for company!BTW - in case anyone got the wrong idea, I didn't write it! I've known the tune for a while, and picked it at random from my collection!
Sorcha - I would think that the reason why you still get the message is quite simple. With all the mucking about you have ended up with more than one copy of the file in different folders, and the one you tried wasn't the one you'd just saved.
May I suggest you create a folder on your desktop, and save the file as MIDI-0 there? If you also have a shortcut to MID2TXT in that folder, it will simplify the operation, and reduce the risk!!
Also, 'explore' your C: drive, select 'tools' and 'find', put in the filename and see how many copies of the file there are (and where!), and do a bit of tidying up!!