So we've found a small bug in Hotmail when using the SAFER/IE stuff (big thanks to Kody Dickerson to alerting me.) Turns out Hotmail will hang when you start it up if you have Hotmail running under a SAFER context, and MSN messenger running as the "normal you".
The issue is a COM object trying to register under a different account, and in this case, the restricted token behaves like another account.
There's a COM object used within Hotmail to determine which of your MSN buddies is online.
If you start Messenger, and then start Hotmail in IE, IE will hang for about 3 minutes.
The work around is to exit Messenger and then open Hotmail. After you sign-in to Hotmail, it will launch messenger and the integration should work just fine!