Hi James.. I can feel you!! I've been having the same problem with my messenger since i updated it to version 14 (2009)..
So i could sing in but after a few sec i'd get the "stopped working" message.. For weeks i was trying to find out something about it, with no luck though..
I tried to mail the Windows Live Messenger Technical Support (if you don't trust my reply or other responses, you should do it too by going to
http://support.live.com ) and they send me an email with several things that i should give a try..
So don't worry mate! Every problem has a solution!!
Here is what worked for me:
1. Go to C/ Program Files/ Windows Live and enter the "Contacts" file.
2. Delete the wldlog.dll file.
3. Then right-click the wlcomm file, click Properties, click the Compatibility tab and under Display settings, put a checkmark for Disable visual themes.
After those steps you'll open your messenger and you won't have the problem any more..
Please post here to tell me if everything went ok or if you need further help..
Greetingssss
/ 
