Activate Office on Windows Azure. MSDN premium subscription. Stop/Start Virtual Machine requires new activation

I installed MS OFFICE on a windows AZURE virtual machine

The Virtual Machine was created with my MSDN premium subscription

I activated the Office with a key from my MSDN subscription 

ALL good.  OFfice works fine,  etc.

I stopped the VM.

I restarted the VM  

I opened office.   It made me reactivate.   :(

How do you properly activate the OFFICE using the MSDN subscription.   THe licensing white paper seems to say this is allowed.

Thanks

David

David Nelson