Just to help anyone else out.
Whilst installing a 2 server QlikView cluster I was unable to licence the second server.
All services were running fine on both servers under a domain user which was added to a nested domain admin group in the local administrators group. The group policy disallowed adding the domain user directly to the local administrators group (common) - however unless the domain user was added directly, when adding the second QVS to the cluster, it would fail licencing the second server.
Hope this helps anyone else out there!
Q.