As I wrote
here for almost a year ago, I have a problem with some contacts that the messages I send to them do not get sent unless they have said something recently. When I log out I get a number of error messages (as many as messages I have tried to send unsuccesfully) saying (translated): "We could not start a conversation with <username>. You might want to try again."
Thing is, the problem has never been gone, it has always been like this. And it's extremely annoying. If you are gonna suggest wait, then don't bother, one year has passed and I think that is a pretty decent wait.
More interesting information: it's not my connection as it happend when I was at a LAN aswell, excactly same thing as at home. I have tried to re-install Messenger but that didn't help.
Currently I'm using WLM 8.0.0792.00 and MP!L 4.01.0.240.