Windows Live Messenger Duplication problem

Hey today when I logged on I noticed that my groups of contacts were doubled. I had x2 of everything and all my contacts were everywhere. They were all messed up. I have a hunch its because I restored some files, but it was working after that as well. I'm worried it could be a virus, any one got any ideas on whats going on. By the way I have the newest version so I just hope its just a bug. Help will greatly be appreciated.

Thank you
Max