Tom has a post entitled MSN Messenger contact card problem where he writes

When MSN Spaces first became available, I signed up for a test space, not knowing what I would finally end up with.  I liked it and thought it was cool that from MSN Messenger 7 beta, you could navigate to my Space from my contact card.

I deleted my first Space and created this one, having decided I would maintain it and wanted a fresh start.  ("MrTom" as a Space URL was already taken, unfortunately...).  But know MSN Messenger still displays my original, deleted Space, and clicking the links takes you to a 'page unreachable' error.  Ugh.  Restarting messenger, changing my messenger profile, waiting a day or two didn't fix this.

I first contacted messenger tech support and asked "how do I" fix this, and they gave me some nonsense about changing my display name.  They didn't understand my problem.  This is probably because "how do I" questions get routed to the most basic tech support pool.  Now I've contacted the "I need something fixed" pool, and gotten a good response.  They don't understand the issue, but they're looking into it and will let me know.  That's all I expect for the interactions between two beta products.  I'm crossing my fingers they can fix this without me deleting my site and recreating my passport. :)

For now, only the most random of people might read my blog, rather than my messenger buddies.

This problem typically occurs because MSN Messenger has information about the deleted Space cached. A tip I got from the MSN Messenger folks is to clear your browser cache and delete the contents of the folder C:\Documents and Settings\YourUserName\Application Data\Microsoft\MSN Messenger. This resolves the problem in most cases.

It should be noted that deleting that folder deletes purchased MSN Messenger content such as emoticons, backgrounds and theme packs. If you've purchased content for MSN Messenger and are having the problems mentioned above do not use the above advice as a way to solve your problems. Instead, contact tech support for alternate solutions.