Applications :: Sign In To Microsoft Messenger Failed Because The Service Is Not Responding?

Now I know that a lot of people have had this problem in the past but I'm hoping that maybe someone will have a solution now that actually fixes this problem.When I attempt to sign in I get the error message "Sign in to Microsoft Messenger failed because the service is not responding. The service is not available or you may not be connected to the internet."

I've tried deleting every trace of msn and reinstalling it, Which did not work. I've also tried upgrading to msn 8 beta (Which incidentally crashes when I try to open it) and downgrading to 6.0.3. Neither of these fixed the problem. I've tried resetting my router, which had no effect. I've tried disabling proxies but it turns out I don't have any so that's not the problem. I've looked at the firewall but msn is not blocked.

Other clients such as amsn and adium are not experiencing the same problem. Msn is working fine on my macbook and other windows machines in my household. It is just my Imac that seems to be having the problem.I have scoured the internet and nothing I have found has been of any use.