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!