Hi,
I have been having a lot of trouble with Messenger 2009. I have tried all the things suggested in the help forums that I could do. I can get Messenger to work afteer uninstalling and reinstalling, but after a reboot I get the same error message 84cc0020, Conact list not available, try again later. I got so frustrated I installed Messenger 2008, 8.5 version. I am not having any problems with this version. Just for the heck of it I tried to upgrade from 8.5 to the newer version, but got the same error message again so went back to the 2008 version.
I hope this helps someone
