Soft Synth Bleed Between Tracks

This sounds like something you have set up as part of the routing of the project. If you create a clean project with the same instruments do you have the same issue? 

On the existing project there are 4 soft synth tracks, and ALL of the horn tracks bleed faintly into the True Piano track.  I soloed each to verify.  None of the horn tracks have bleed from any of the other tracks. So I created a new project with one True Piano track and one horn track.  Everything was perfect - no bleed.
 
I then went back to the original project and set the output for the horn tracks to none.  I still heard the horn tracks on the Piano track, though it only sounded like the sax (it was very faint, so not sure).  How can I possibly hear sound on the Piano track when all of the outputs on the other tracks are set to none?  There was no send on these tracks and I turned off all of the FX.
 
I then thought I would paste all of the tracks into the new project since I wasn't getting any bleed.  This created a new problem.  Though I copied track automation (which for me is just volume), when I pasted into the new project the volume automation was added as a separate track, so it didn't affect the original synth track like it should.  This won't work because I have A LOT of volume fades in the project!
 
I did notice one difference in the new and old projects.  When I selected outputs in the new project, some the drop down options were "Master, Metronome and Preview".  In my old project these options were replaced with "A, Aux1 and Aux2".  The new project has Master as the output for both tracks, but I don't have the choice to select Master in my old project.  How do I change my old project so that I get the same output options as my new project?  Do you think this could be the problem?
 
This is SO frustrating!  Any advice anyone?
 
Thanks,
Dev
 
 

Your tracks or even the whole project could be corrupted. I'd start fresh with a new project.