z3ta+2 arp speed problem

hi guys!

Using z3ta+2 (and z3ta+1) i'm trting to map a controller to the arp speed using the mod matrix.  it seems that whatever curve i select, the assigned controller does not change the speed.  i'm working around this right now with midi learn in the synth to hard wire it to a controller, but really wish the mod matrix would do this.  is it me, my install, or z3??? 

thanks
vid