Thank you both for your replies, it's much appreciated.
I am very much aware of the "diversity" model fiasco, and rang Hauppauge the other day to check it out (as I thought this was a diversity model). The chap on the phone assured me it was not. "But it's a 'TD' and not a 'T'", I said - no, it's not a diversity. "But it has 2 antennas" - no, the second one is a dummy, only 'ANT1' is actually connected to anything! Obviously, I took this all with a pinch of salt.
I've been having another problem since I rebuilt my core (last motherboard fried, so new build had replacement motherboard, and this new TV card) - when starting the machine, it would freeze on either the very first boot screen, the grub screen, or the kubunutu loading screen (seemed to do something different every time). Anyway, moments ago I removed the NOVA-TD-500, and the core starts up fine.
So indulis, I'm sorry you went to the trouble of posting these instructions for me, but I think I'm going to get rid of the card and try and get hold of the older version that I already have. Hopefully Hauppauge will swap it for me.
Thank you both again.
Well if it has the twin aerial sockets... then whatever Hauppauge told you its definitely a TD in our experience. Returning it sounds like the best option.
All the best