I'm using Metro 6.3.8.6 and Quicktime 7.5 on an old iMac G3, which I haven't used with Metro for quite a while. I've imported a MIDI file and set it up to play thru the internal ports, for a quick audition of the MIDI file. Problem is I cannot hear any sounds. Meters rise and fall, but no sound. Is there a problem with this particular version of Quicktime?