Just my 2-cents worth...
Ubantu, by default, does not sets up root user when setting up. So if you tried to login root, naturally it will reject, independent of password you use.
You just use sudo to perform root priviledged operation. I was able to login lucid / lucid for both LCD and the console.
Since I deal with a few other systems (and I am not sitting in front of 53QSB right now) perhaps I am confused but I thought sudo (root priviledged command) with password lucid worked.