Windows live messenger and lsass.exe problem

Hello,


I installed Live Messenger 8.1 today, and After logging in, (or during the
logging in final process before it gets to load your contacts), lsass.exe
goes to 100% CPU usage and nothing can stop it apart from ending the Live
Messenger task from the Task Manager. I have checked and am not infested with
any Sasser or other virus.

I just tried signing in with a completely new MSN/Live/Hotmail.com address.
Same thing occurs... and I had the same behavior with Live messenger 8, but
not with 7.5...

What can I do?

Thanks in advance.