Very strange MSN Messenger 6 problem

[Edwin Verhoeven]

Hello,

since two days i get this strange error in MSN Messenger
(6.0.0602) saying "We can not start a conversation with
*****. Please try again later"

I can sign in correctly, every other function works
correctly, except for the messaging :(

Is there anybody who can help me with this problem?

PS. Sometimes it suddenly works again (very strange!!)