pitch bend won't work on garageband

I'm having a problem with the pitchbend for an individual track, and the weird thing is that it works sometimes and other times it doesn't. i'm going to pitchbend on the bottom track info and creating the dots up and down, but when i play the track the sound is not bending up or down with the pitch. also my midi axiom keyboard is not bending the pitch when i move the wheel up and down either. none of it makes any sense. could there be a problem with the software?