As stretchs said, its a new login error message. The old message would say if you had your email or password wrong. And with having to increase account security the error message was long overdue for a change.
If I was you and your sure you type everything right and still get the error then you would need to contact support. Just remember passwords are case sensitive so there might be a capital letter you might have missed somehow. I sometimes hit my caps lock and not realize it.
http://www.guildwars.com/support/default.php
Make sure to have your keys because they will ask for them. If you don't have them anymore I have heard they can still retrieve your account but they would pretty much need your life history. If you have all your keys then things will go smoothly but it still may take a couple of days or so. Just keep checking with them, but realize this could take a few days to get straightened out.