Double triggering

Having bought a new Axiom Air 49, I'm experiencing set up problems. The latest one is that any midi notes I record are OK until I quantize.What's happening is that when I use the Axiom in Pro tools 11, I get double notes that overlaps each other and you can only see them if you move one set of notes up or down, or that you quantize. Not being a techie, but a lowly guitarist, I'm not able to work out what to do.:confused:

Any assistance would be gratefully received.

Al