I have the opposite problem. Hotmail works, but my @gmail.com passport does not. It sits there at the signing in screen forever. There is *NO* error message. I've left it sitting for over 8 hours while I slept. It just kept on signing in. I've discovered that I can still login through windows messenger with the passport, this is a problem strictly with WLM.
http://shoutbox.menthix.net/showthread.php?tid=67262 It seems to be a similar problem.. Identical except for which types of accounts can login.
