On projects with midi playing back if I hit the stop button, go to different measure, then play, sonar 8.5.3 plays the last midi note it was playing previously along with the correct audio/midi at the new measure. It's like it is still in the audio buffer. I have unchecked play audio tails. I essentially have to hit stop, then disengage the audio engine, the reengage the audio engine (Which causes the tail in the audio buffer to finish playing and fade out), then hit play to get only the current audio/midi to playback alone correctly. How can I correct this? Thanks

I have the same problem and it's so frustrating. It even shows up in exported tracks sometimes, for example when a new midi instrument comes in at a certain point in the track, you can hear it playing a bit of the tail of another note before correcting itself. It's annoying enough in Sonar, even more annoying when it actually effects finished projects. I think that it might have something to do with midi input channels but I'm really not sure.

Just check "Play effect tails after stop".

Hopefully you are using different channels for different instruments. In the old days you had to work that way, but now you can have every soft synth using Channel 1. Don't. 

I never have that issue and I think this might be the solution.