MSN Live Messenger Freezes when you start a “Group Conversation”

So at my work, we have this lunch guy who comes around noon everyday and everyday Lindsay (aka L) sends a group message to a bunch of people at work informing them of his arrival (Thanks L).
But…….Alas…….GOOD DEEDS NEVER GO UNPUNISHED!!
This ALWAYS and I mean A L W A Y S freezes my Messenger for atleast 20 seconds until everyone is done either replying to this conversation or leaving the conversation. It’s like a forced break for me.
Why Microsoft Why?