Spent a half hour figuring this out...

[Dante]

I sat down to rock out with my headphones on and the ADA rigs (MP-2 and MP-1 Classic). I have the quad switch set up to toggle 4 effects in my GX-700, so it's like having 4 stomps in each patch. One is always an EQ boost for solos. Well, that dang ol' quad switch wasn't working for some reason with my MP-2 and I spent a half hour figuring out why....read on

First, I checked the assign numbers in the GX-700, which I haven't changed or touched...they're correct...that's not it
Next, I checked midi cable (even though it's switching patches just fine) and all seems plugged in fine...that's not it
Next, turn everything off...unplug the quad switch cable and plug it back in, turn everything back on...that's not it
Next, I dig up the MXC manual to make sure my pedal isn't wonky...checked the midi channel, switch assignments, etc....that's not it
Next, I decide to try the Classic rig, which behaved the same way...that's not it

I walk away, have a sammich...come back later & double check all the connections

Turns out, I had plugged my quad switch into the PEDAL jack instead of the SWITCH jack 

[rnolan]

Well that will do it LoL

[MarshallJMP]

Well that will do it LoL

+1 :D Well it can happen.

[Harley Hexxe]

Hey Dante,

    You're not the only one to plug in equipment on auto pilot and later figure out you plugged in a wrong connection. I've done it too, many times.

Harley 8)