MSN messenger error - cannot sign in - certificates

Ok it's like this:

Every time i try to sign in it sas either my date and time is incorrect (it is correct!) or my digital certificate is not valid.

Now gues it's the second one, since i basicly tryed everything else and i cannot find the answer. I have two certificates in my keychain folder and i dont know if they are only ones tat should be: Microsoft IntermediateCertificates and Lorenzo (which is my computers name)

I am not behind proxy, i am in my company, everybody that uses winows here messenger works and i deleted messenger and the preferences and reinstall many times. SO PLZ HEEEEELP!!!