Problem specifying midi channels for controllers [cubase 6]

I want to have a controller (mpk49) send on one channel for keys, another for pads.

I’ve set up a midi track with a corresponding VST instrument - this allows me the option to select the midi channel that (I presume) should be carrying the signal from the controller (1-16 +any). [note ‘Instrument Track’ doesn’t seem to give this option]
Thing is, when I set it to a channel, it’s still accepting signal on all channels from that controller. I’ve tried it on multiple controllers, same problem (and none are set to broadcast on “all channels”). Also, “all midi” is unchecked for the controller.

Something simple I’m missing here?