When I opened Skype/Messenger yesterday, my "Coworkers" list was suddenly empty. I took a minute to refill my "Coworkers" list, and it was fine yesterday... but today it was empty again!

I went to profile.live.com - my lists there were totally different than my lists in Skype/Messenger. I rebuilt my coworkers list there, but that's not reflected in Skype/Messenger.