Printing and CUPS, osX 10.3.9

I'm trying to access the CUPS printer setup utility on http://localhost:631, but when I click on the Administration tab, it asks for a username and password. I've tried all the combinations I can think of but have failed.I'm sure I've never accessed this page before so I can't think I've even set up a name and p/w.
Anyone got any tips for me please?

 

Done a bit more research since posting and it turns out that since 10.3.4 the password for this page has changed - it no longer accepts the root or admin user names and passwords. Apparently this can be changed in Netinfo Manager, but having just tried it and messed up both the root and my own admin user account passwords and frightened myself more than a little I've decided that I really can live without accessing this page!