If I understand you correctly, you're having issues with one track driving a different synth than intended? If that's the case, I've had it happen when the MIDI controllers being used are different than what was connected when the piece was originally done / saved. In my case, I had an Arturia Beatstep, a M-Audio Axiom 25 and a Novation SL MkII connected. Later I opened my project with only the SL MkII connected and experienced a "shuffling" of the outputs on my tracks. Suddenly Track 4 for instance was playing the synth assigned to Track 2, etc. If you look at the "Output" field for each track, you can see which synth / track they are currently routed to and make adjustments. It should get you back to what you originally had set up.
On the other hand, if I completely misunderstood the problem, let me know and I'll give it another shot.