Scratch

I've had this problem some times before. You go to other websites or games that use accounts yes? Maybe if you delete your cookies or temporary internet files. If your using IE, CTRL SHFT DEL, would open the window necessary to delete them. This doesn't always work, but it's a solution on another site I've been to, on why they appeared to not be logged in. (Unless I'm reading your error totally wrong!  )

Regards,
   Ralphjos