Hi, welcome to the forums, we can't really help with so little information.. but I'd suggest you try the SVN version of aMSN :
http://amsn-project.net/wiki/SVN there's also a PPA for ubuntu that will make your life easier (the thread is sticky in this forum). try that... if it still fails, paste the protocol and status logs (Ctrl-D and ctrl-S from the main window)