Unable to install license

I have registered and received my licence, the Firewall is running and I can get to the internet. I get prompted that there is no License when I open the XSentry Client, I install the license and it prompts me to restart the firewall and the client. I restart the firewall and the client and log back into Xsentry, which then tells me there is no license installed. Can anyone suggest a solution as this is driving me mad, I have enabled the license negotiation in the FW console, the license is for Eth0 (Wan) still it does not except it.

I noticed that there are no replies here. I had the same problem untill I registered using the MAC address for the eth0 NIC. The first time I registered I gave the MAC address of my workstation computer. The registration form is not very clear as to what MAC address to use.