it was a typo that caused the problem - thanks for spotting that. All ok now with the full name of the proxy server.
Regarding MTU: -
This second PC is on the end of a 40M Ethernet cable from the router and I did the ping tests and got a maximum value of 1430b thus giving a MTU to set of 1458b.
The other PC (and I checked again) gives a max of 1402b to give the 'usual' 1430b MTU value to set.
I wondered why the 2 values are different; I will check the second again though.
The WAN set up page on the router (DG834) says the MTU is 1458b; mine at home says 1500. I've not actually set these values in the router.
Does the router 'decide' this value?
Terry.