Cannot login using account name

Hey, I just downloaded Wotlk. I've created an account and verified it via my email. When trying to log in for the first time, it says the information I have entered is not valid (refer to pic)

http://i.imgur.com/SNCdT0p.jpg

To confirm, I'm using my account name (not email address), the password is correct (checked several times), I've tried restarting game, using my forum name (just to test it), and I can't figure it out.

Any help would be appreciated.

Cheers

Make sure that the realmlist in \Data\enUS\realmlist.wtf is set to logon.warmane.com
Furthermore, can you connect to other expansions?

Thanks for your help Zelta, after trying a few different things (including creating a new account, hence the new name) I figured out that the 18 character password I was using was too long!

I created a new 10 character password and was able to login immediately.

Thought I would leave the fix here to hopefully help others.

Thanks for your feedback, I will keep this in mind for future replies.