Shoutbox

A system restore will be of no use to them

If you log into hotmail, do all of your contacts still show correctly (the hotmail contacts and WLM contacts is a shared list)

If so then there are instructions to remove the local cache of the contact list and force messenger to re-download it from the server (which I can give to you if your contacts still show correctly on hotmail, because this shows that they are still correctly stored on the server.

If they do not display under the hotmail contacts menu then I'm sorry but it looks like your list has been lost.  You can try to re-build it from the Messenger Plus list of "Contacts who have you", as this lists all of the contacts who have you in their contact list and as such should comprise all of the people who you had in your contact list