I need help with Reason 4.0 w/ m-audio Oxygen 25 MIDI keyboard

I have an M-Audio Oxygen 25 MIDI Keyboard and use Reason 4.0. I used these two together years ago and they worked fine. However, now I cannot get Reson (or GarageBand or any other DAW) to detect the Keyboard. They always say that there are 0 audio inputs detected when it's plugged in, and I have tried using several different cables to see if that was the problem (which it wasn't). I have no idea what to do, I just need some help!