Importing Standard MIDI files from an IBM formatted disk when running 7.5.3 OS does not create a translator type on the floppy or hard disk. As 7.5.3 does not use Mac File Exchange, you have to set a translator to the .MID file on the floppy or hard disk. When Pro Tools is chosen as the translator, it still won't open these files. However, if you choose a sequencing package such as Vision, or Logic as the translator, it opens every time. Once one of these packages opens the file/s, and then save it as a Mac midi file, it will open in Pro Tools with no problem.