I entered my full username @virgin.com and tried both my account password and email passwords.
I set the VCi to 38 as per the settings on the Netgear router. Only difference I can see is the MTU is set to auto and it was set to 1458 on the Netgear.
I don't know if this is still the same but about 5 years ago a friend of mine was on virgin ADSL even though his email was firstname.lastname@example.org
or .net cant remember his ADSL user name was something like email@example.com
and had a different password to his email account he had to ring up to find this out before he could get his router working.
Hope this is some help
FTTC 70000/23828 kbps Bigtv+
IPTV Package 588M from the cab 6dB snr 22Aten