Hi Jonathan
In the end you were absolutely correct. With the pfsense VM down it was possible to access the unraid GUI via the fixed IP of the server. It was all a bit odd though as I'd first tried it with a Windows machine and no matter what I did it just kept coming up with the XXXXXXXXXXXXXXXXXXXXX.unraid.net. I then had another go with a machine running Ubuntu and that worked without any problems.
Thanks for your help.
La France