Mac filtering is nothing to do with Macs. It's another layer of security. It stands for Mac Access Control address. On a wireless network each device has its own unique Mac address. You can list in the router the Mac addresses of all the devices on the network and tell the router to allow ONLY those addresses and nobody else to join the network. So even if you could *see* the wireless network (which if you've configured other security properly you shouldn't be able to), you still couldn't join.

As you've probably figured, if you tell the router to make you DMZ, you have no firewall etc. Gamers often have to take advantage of this feature if port forwarding doesn't work for them.

Thanks very much for all the links. Food for thought. I understood much of it, but will have to give more thought to a static IP address, obviously

In theory (and as you know) port forwarding requires a static IP address so that you don't lose the forwarding after a reboot when you would usually receive a different IP from the router. Port forwarding should however work at least until this happens, so in theory it could be tested without actually setting up a static IP. I can't get port forwarding to make a difference, so will give the of a static IP address some thought for a couple of days, as I have reached 'router overload' presently...lol....and would prefer to come back with a clear head.

Once again, many thanks for you help :-)