evo nesto korisno sto sam nasao na google :
a. Sign out of Messenger.
b. Click "Start," click "Run," type the following command, and then click "OK":
%USERPROFILE%\Local Settings\Application Data\Microsoft\Messenger\
c. A new Microsoft Windows Explorer window opens. In the window, click your Messenger ID.
This is the part thats diff:
Click on FOLDERS (menu bar), i assume that you can now see your username in the left hand pane!
Click that folder, so that the subfolders show, now one of the should be "Contacts"
DELETE IT
Worked for me, all contacts back in place!