the error 0x81000306 means "The logon attempt timed out after 15 seconds."....
In other words there is something wrong with your connection to the msn-servers...
Have you tried to completely uninstall MSN Messenger, redownload, end reinstall a fresh copy (without any patches, skins, addon, etc..)?
Have you tried to kill any other application that you have running in the background?
Also, refer to
http://shoutbox.menthix.net/showthread.php?tid=20295
and check the checklist (also note the added points in my post there). Do this very carefully and point-by-point. This means, reboot after each tried point...
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