Hakumi's pretty much explained it, there's a 16 character limit for both username and passwords. Passwords can be fixed by clicking the Forgot Password in the Registration box at the top of the page, but usernames don't have a solution. You'll have to wait until Registration is open again to make a new account.
Here's a few tips for that:
1) Make sure your username and password are NOT over 16 characters.
2) Be sure to activate your account STRAIGHT AWAY after registering! Some people have problems with activating their accounts if they wait, because they try it when Registration is closed and it doesn't wanna work.
3) Keep checking the site ever half hour to an hour or so to catch Registration open again, it opens at random times and the staff cannot control when it does, so it'll be up to you to catch it open. If you were lucky enough to catch it once, you'll be able to catch it again.
It's a pain we all know, and they really should clarify somewhere on Registration or where people will see NOT to create accounts with usernames or passwords over 16 characters, to prevent this kind of problem or at least lessen it. Sorry this had to happen to you.
