I have updated several systems from SLED 11 SP3 to SLED 11 SP4 using wagon. In all cases the update proceeds correctly but when the user logs in to the updated machine a window appears titled 'Authorization dialogue' with the following text:

You need to supply a username and a password to access this site.

Site: Basic Authentication for nu.novell.com at nu.novell.com.

There is then an input box for username and password.

What username and password are required and why am I being asked for them? I have tried my SUSE customer centre credentials but they do not work.