I'm in exactly the same boat, I used to mulitbox on my machine with wow and have recently got back into play a bit again and my keyclone just displays 'LICENSE HAS EXPIRED' :(( I would really love to be able to use it again. I believe it was registered on my current system so there's no need to transfer or anything.
Edit: I am possibly using a different NIC in my machine as I added a new PCIx card rather than use onboard so maybe a transfer is needed? Also I've tried on an off for a week, I don't think its a maintenance window issue.