Sorry guys, I tried all that :-(
BT gave me a couple of others to try including :-
user@btinternet.com - password 0 (zero)
bt_test_user@startup_domain
all of which didn't work either.
BT assure me that this is all correct and should work.
The Basic settings for both routers are exactly the same i.e. :-
DNS = auto
VPI = 0
VCI = 38
Modulation = G.DMT
Encaps = VC MUX
Encaps Protocol = PPPoA.
However, I did look on the Netgear help pages and found this :-
http://kbserver.netgear.com/kb_web_files/n101227.asp
This seems to suggest that if you use a different Ethernet adapter or router to set up your internet connection that your ISP might reject the connection request based on the fact that the routers MAC address will be different? Maybe I need to spoof it ?