I am experiencing the same problem and it gave me a few sleepless nights already.
It happened from one day to another, my setup was working fine until this started. I had no updates, no internet even in the studio. Started with one external synth first, now extending to all other midi devices.
After trying a lot of different things, I realized it came from the Push controller, indeed when using it in Note Mode. When Push is unplugged, all systems are fine.
I tried a lot of things, upgraded my Motu128 as well, changed all cables many times. It all comes down to Push having a sustained note sometimes even after pressing just one pad. It messes up the sound even of some synths, sending all kinds of information I don't want.
What I discovered last night, is that when I press Stop button in Live the hold note stops. Even if the main sequencer does actually not run. So there might be something there. Is it only coming on some Push devices ? I have tried it on my older computer, with Live 9.1 + OS 10.6.8, problem remains.
I have updated to latest version of Live last night, didn't help. I also checked all Midi setups possible inside Live (Track only).
Is there anything else we can do ? Anyone actually solved this ? I am also speaking to 'Support' via email. They have been very helpful but I have no solution yet.
I made a small iphone movie to show what happens with the Moog SP. https://dl.dropboxusercontent.com/u/124 ... 15.mov.zip