Midi Controllers - Midi Port Assignment

[eneezy1]

MBox Pro
OS X - 10.7.3
Pro Tools - 9.0.5
MPK49 (Controller / Keys)
Maschine (Controller - Percussion Pad)

I'm assuming the reason I can't switch signal input from one controller to another is because of the way my midi ports are set up, is this correct? Right now I can only get signal input (from my Maschiine pad) using my MPK controller. Do I need to switch midi ports around so I can get signal input from Maschine directly into PT? More ideally, how can I get signal input from both of these controllers? My current midi port assignment is:

MPK49, Port 1
MPK49, Port 2
MPK49, Port 3
Maschine Controller, Midi input port 0

Also, even when I assign the Maschine controller using the I/O assignment in the Mix window, I still cannot get signal input directly into PT (without going through the MPK). Any thoughts here? Thanks for your help!

-E