I regularly find that, if I try to log into the site, after the splash page shows a successful login, I'll be taken back to my original page - but without actually being logged in.
This happens in all browsers (IE, Firefox, Chrome), including when I start a fresh session (i.e. incognito mode and similar).
However, there is one page where I can reliably get a successful login; it's the one where you check your private messages:
http://vgmdb.net/forums/private.php
However, being able to login at other pages is certainly convenient
Any thoughts on what might be happening here?