I was attempting to edit my previous comment but it didn't go through. Anyways, this is what I was going to edit in. From what I've seen, some of your notes are above/below the C-3 and B-5 restriction. You'll have to sift through the drum section as I've seen quite a lot of C-6 notes in there. Once Milkytracker doesn't give you a prompt, then your .mod file will officially be a .mod file.