Ok, if they are of different midi channels on the same track it can be done? Cool, but what if they are not. This was a problem that I had with a project some time back. I have to move on with projects at quite a rate and this was one problem that I had had previously. Your offer to send you the midifile in question is great and will do so next time. I was about to offer that same solution to the guy struggling with Fit improvisation but we got it sorted :).

Yes if there are different channels it is easy - simply use the CAL split channel to tracks
 
By the way might it also be possible to find another source for the SMF? As we all know there are MANY different repositories online and for a lot of them they are all the same SMF...could be worth a shot..

Thanks! The other issue when they are the same channel is still open to comment. I was steering away from using a quantize to bring the hidden notes to the same start time to make it easier to filter as you don't always want to do so with a well played midi track with a nice feel.

What does the event list view (alt-8) show for the "combined" track? If there are different channels it will show up under the channel column...
EDIT: avoid using quantise in any way shape or form. It will definitely make it impossible if you do that.

One other option, although REALLY time-consuming is to use the split notes to tracks CAL..You will end up with lots of created tracks, but it might make it easier to discern what you want to retain and discard.

Sorry to revive this, but undupe doesn't seem to work anymore.  And the Select by Filter doesn't seem to work either unless I am not understanding.  Can whomever explain explicity how to use SbFilter to get rid of hundreds of dupes?