Asus N56U router username limited to 20 charactors - help!!!!!!!

[#1]

Hi all
Trying to set up my new Asus N56U router but it limits the Username field to 20 characters, but I need 23, so cannot connect to Plusnet!!!!!
Any suggestions as to how I can get around the limit please.
Stuck at the first hurdle so would appreciate your help.

[#2]

I haven't got one of these, but the thought that occurred to me was whether you might be confusing the user name for logging in to the router interface with the PPPoE login name for the WAN connection.
Given how popular these routers are I cannot believe this wouldn't have come up before.

[#3]

Are you trying to put the username in   Advanced Settings/WAN/Internet Connection/PPP VPN Client Setting? thats where your @plusdsl.net username goes in.
If your still stuck on the login to the router page that pops up before you can get to any settings the default is Username: admin, password : admin, all lowercase.

[#4]

Hi spoon whittler and Dhaos
Thank you both very much for your help.
As you suggested I was suffering from newrouteritus and trying to log in to Plunsnet via the initial Router Login screen.
All ok now thanks again for your help.