I've reported this before but it was either ignored disregarded or something I forget it was a while ago so I'll do it again with some screenshots this time.
This is a conversation with my friend.
http://img137.imageshack.us/my.php?image=lucy1hd8.jpg
The conversation has just been opened and it maximizes by default (this may or may not be relevant).
I now restore the conversation to a window, and then maximize it again.
http://img174.imageshack.us/my.php?image=lucy2zy8.jpg
As you can see not only has her name formatting been added but the start of her name which had been previous cut off has been restored as well. This has been evident in MP!L for several versions, over multiple operating systems, windows installations, Windows Live ID's and even different computers, so it is reproducible. Of course any name which does not include formatting at the start (or in the name entirely?) do not suffer this bug.