Well… did you check your midi-settings and all that?
Is that synth on the same midi-channel as your machinedrum?
You can change patterns on the machinedrum via program change.
so if you share midichannels on your synth and your machinedrum
strange shit will happen… especially in songmode where you keep on changing patterns which triggers the sending of program change messages.
So give your octatrack its own midichannels. the machinedrum its own midichannels
and your synth its own midichannels to play with…
it might be nice to read up in the manuals, how to prevent them from sending midi.
in my setup, it works allot better, if the octatrack only sends out midi to controll other things, like timecode and clock… but for example not the button-twiddling.
unless i use a midi-track for that…
Mine was doing this about a week ago. Im not exactly sure how it was happening, but my speculation is that i accidentally set up a midi track to do some funky stuff to the mduw via ARP settings on the OT. I was trying to midi through my synths and make sure everything was listening to the OT and in doing so, the mduw started going crazy. I believe what was happening was that the ARP settings were sending midi to the mduw corresponding with pattern changes and/or song mode. I played with it for a bit, and found that it was actually pretty cool, but was still unsure of how it was happening exactly. In the end i reloaded my OT project to its template state, and the problem/happyaccident was resolved. Ive yet to try to recreate it, but i have a feeling with enough effort, it could be a very useful tool at some point.
As stated above, its likely a midi channel conflict. In my case (also stated above) i had a synth on Midi ch13 which is where my MDUW base channels are set. Ive changed the channels in my synths as to not conflict with the mduw.
Check your MD globals to see where your base channels are set, and then make sure all other synths are off those channels.