what are you trying? if it is the Speedtester.BT you put in your home phone number, where you are calling from and where your broadband is, then when it asks the next question it is the username that you put into the router when first connect, it is not your e-mail address.
If you want your profile that PlusNet have your will find it here
https://portal.plus.net/my.html?action=data_transfer_speed, you will be asked to log into the User Mebers site the will be presented with the info.
Also did you look at the answers to your first question?
http://community.plus.net/forum/index.php/topic,75418.msg602426.html#msg602426 you did not reply
