Go to the folder C:\Documents and Settings\Username\Application Data\Microsoft\MSN Messenger\number, with Username being your Windows username and number the number that symbolises your email address. Clicking Start > Run and typing
%appdata%\Microsoft\MSN Messenger should show the folder that contains the numbered folders right away.
To find out what number matches your email address, download
http://shoutbox.menthix.net/attachment.php?pid=291329 and enter your email address. Clicking Generate will show the number.
Go there and delete the folder called UserTile. Reboot and add your display pictures again; your problem should be fixed.
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