After hours of fine combing forums, I have gotten my Oxygen (V1) to work on my Mac Mini (March09). It was detected in MIDI settings but no signals were recieved when I played. Also, neither Reason, Logic nor Garageband could detect it. Now they do!
There seems to be a problem with USB powering of Oxygen 8 of newer versions of the unibody, mac mini and iMac - according to forum posts. The simple fix is to do the opposite of recommendations of m-audio and use a usb port of a powered usb hub.
For me, I worked as soon as I inserted it into my apple keyboard.
Simple as that. I hope it helps you guys too!
Cheers!
Jonas, Sweden.