This is something I suspected would come up soon enough and is likely due to the way the IP verification determines its own address. I'll try to make sure we address this in the next update, but for now a temporary fix that should work for servers using a different BindAddress is to use the following line to set the IP check variable manually:
$IPv4::InetAddress = $Host::BindAddress;
If you pop this into any file that loads before our scripts are run (maybe create a new .cs file to pop in autoexec if you run multiple configs) it should be fine assuming it's set to the IP the clients see.
I'm asleep at the moment myself, but in the morning I can open the script on our end and check it out.
Edit: I've updated the installer with something that should fix this particular problem (as well as an uninstaller, but that's unrelated). If you don't want to download the whole thing, you could just replace your existing T2csri.vl2 with this: http://www.tribesnext.com/krash/T2csri.vl2