1/2 SOLUTION TO BUG:
I faced out the problem: how to reproduce it: invite multiple people a
time to a chat-room conversation (click Invite, and select more than
one person a time). If one of the nicknames is longer(or contains
strange characters - like Plus! character for colors) Live! messenger
crashes (frozen with 100%cpu usage). this appens also if when you are
in a chat-room with multiple people, someone with unicode chars in name
logs in,a dn you click on the balloon notifying the access (the balloon
that pops up near the systray).
it's a unicode buffer overflow bug... and I think is a security hole
too! can be used to execute code...