WotLK Strange problem with login-screen

[Jissux]

A few days ago a problem started to appear when changing realm. This is what is happening:

I open wow, type in my password, getting in queue to Lordaeron since I'm most active there. I see the huge queue and decide to play on Blackrock instead. When I press "Change Realm" the "queue-box" disappears and I'm back to login-screen... So I enter my password again but this time when I press "Login" it erases my password and nothing happens.
It's an easy fix, all I need to do is to restart wow, but it still bugs me.. I want to find out what it is. Anyone have the same problem?

[Agramon]

Try to clear your WTF folder. Keep in mind it will reset addon settings if you are using any.