Shoutbox

You can try to fix it by removing the directories:
%userprofile%\contacts\XXXXX
%userprofile%\Local Settings\Application Data\Microsoft\Windows Live Contacts\XXXXX

where XXXXX is your email address or your MSN User ID. Which can be calculated here

NOTE: some folders may be hidden...to unhide them go...Tools -> Folder Options -> View -> Choose "Show Hidden Files and Folders" -> Click on OK. Then make sure once you are done, to change it back