This is now working.
I corrected the startmeup file and also had to connect the NVPR server and the NMT to the same router, it was previously on an additional switch. The NMTSystem check is still not returning the MAC address so i'm not sure if there are any other issues at the moment.
Thanks for all your help.
Glad you got it working, if you have other questions let me know. And extra switch shouldn't add a problem, I use two in my network without issues. Maybe you have a netmask problem on your router. Since NextPVR is getting your MAC that probably is just an NMT syntax check issue.