I just wanted to share my brain fart in case it saves someone else the absolute panic attack I had last night!!
Last night I was prepping for a weekend of shows and my Pro 2 was acting crazy whenever it was sent a midi note to an arpeggiated program. Like really crazy. It was like it was just picking random parts of the sequence to play and the rest if the notes were dropped or sometimes an octave higher.
I spent an hour going through my sequencer (OT), my midi thru boxes, my cables.... a lot of cursing and wondering what the hell was going on and what (if anything)I had changed since my last show a couple weeks ago. I was sweating hardcore!!
And then I realized ARP SEND MIDI NOTES was ON in my globals. I had turned it on last week while doing some recording. REJOICE!
Why does this matter? Well, in my live set up, I have midi information coming in to the Pro 2 as well as going out of the Pro 2, so in a track where the Pro 2 is getting midi note information from the OT and that Pro 2 patch has the arpeggiator turned on, the Pro 2 was sending midi notes back to the OT at the same time on the same channel as it was getting them, essentially cancelling itself out but letting the odd note sneak through and causing some chaos (octave changes??) to boot.
So that's it. Don't have your ARP SEND MIDI NOTES on unless you're using it at the time, it's a real trip if you forget.
Hopefully this helps someone. Ha, maybe even me as I'm pretty sure I went through this same lesson last year.