Did the instructions say anywhere that you need to give your password? Because if they do, I need to correct them. Please point out where the error is, please, please, please!

What it looks like is that somehow, you have already successfully logged in, since the log-in page did not appear.

Note that on the sign-up page (http://www.katspace.org/fiction/ficathons/finish-a-thon/2010/sign_up/) you should give your name or pseud, not your LJ username. That comes later.