not sure about max 8, but older versions of detonate have a very low PPQ resolution which regulary fucks up the timing of midi files or max-created data. (in case i am not up to date, someone pls correct me.) my personal solution for converting max-made data to midi files was always to write stuff in real time into a DAW app using a detonate-pluggo. this is in most cases of course limited to 16 channels or channel 1 of 16 tracks, because DAWs usually dont allow a plug-in to output on more than one "port" or "bus", so for more than 16 channels you´d have to record more than one time in realtime. :) splitting any kind of midifile with more than one track into different midifiles of one track each should also be made with a midiplayer or DAW app, IMO. it is very easy there. inside max and in discrete time... your best bet is to use java (with the usual midi libraries) i think.

Thanks for the detailed reply, Roman Thilenius. Could you explain the 'detonator pluggo' a little more? I actually (embarrassed) don't even know what a 'pluggo' is.