I dunno what would cause that Flob, but in order of suggestion...
1) If you are still using IE,
get Firefox !
2) If you (for some reason unknown to man) still want to use IE, at least make sure it's IE7.
3) Clear all cookies specific to any of the mistmoore.net sites, including beetlejuice.dk and eq2.dk. Also clear your offline cache while you are at it.
4) Check your browsers advanced settings. You may have some weird security setting set that prevents the site from updating your cookies, hence having you submit invalid information regarding your session.
/Deb