Analogue-sequencer

> > Sounds to me like it's receiving the start / stop but NOT 
> MIDI clock.
> > Could you replace the P3 with something else on that MIDI port and
> > determine whether MIDI clock is reaching there?
> 
> Yes, attaching the same cable that comes out of the MPC 
> directly into  
> the andro or v-synth controls the tempo on both of them (arps).

I'm pretty sure I've identified the problem.

Your MPC must be sending a CONTINUE at all times, never a START.
Receiving a START message will make P3 switch to MIDI clock, but if it has
never received a START, when it is told to CONTINUE it will still use
internal timebase.
IMO the MPC is not behaving properly - you should START at least once before
you can CONTINUE.
You can workaround this by setting the user conf option 'Start on cont'
I'll add a bit of code so that CONTINUE is always treated as START if there
has never been a START.

Best regards,
Colin Fraser
Sequentix Music Systems Ltd
http://www.sequentix.com