Hi, thanks for your reply.
I have managed to fix the problem and am sharing what I did in case anyone is struggling with this
The problem was the M-Audio driver. Although the Evolution MK-449c is now an M-Audio legacy device and fully supported by them, the driver was confusing Reason (although Cubase etc was fine).
As the MK-449c is 'Class Compliant' I took a chance at uninstalling the recommended M-Audio driver and simply plugging in the keyboard and let Windows do its thing......and viola! It worked! Reason now sees and recognises it.
I hope this might help someone in the future