Hello, I am running into this situation with my MD :
I want to control an external synth parameter using cc, but without actually triggering anything, because I am using the synth’s sequencer (in that case, a subharmonicon, clocked by pulses from the MD). So I set a MIDI Machine with the right channel, and set in that machine the cc number I want (cc 4 for SH VCO 1 pitch in that case). Now on another track, I set an 8P machine (as a way to get « trigless trigs »), and set the values so that it matches with the parameter I want to modulate on the MIDI machine. Hit play. When I manually change the value on the 8P machine, everything’s fine : the pitch changes accordingly on my SH. But, if I p-lock the values I want, it’s not working anymore. The p-locking itself is working of course : I can see the values changing, be it in the 8P machine, or in the MIDI machine. I try with an LFO modulating the cc value, instead of the 8P : same thing. I can see the values changing, but to no effect (whereas when I do it by hand, it works).
However, if, even only once, I trigger the SH via it’s MIDI machine, it’s working (unfortunately the MIDI implementation of the SH is so lame that it’s something you’d better avoid, but that’s another story). I could have expected this kind of behaviour (after all, the INPUT machines want to be triggered once as well), but what I find really strange is that this is not required when changing values manually, only when in an automated fashion (with the visual feedback being indentical in either cases).
Is this known behaviour ? Any chance it could be fixed, since I might be read by the good people responsible for OS X ? Unless there is a good reason for that that I cannot see 
thanks !