I've seen this for a good while now so it should apply to all versions
including the latest.
It all happens when two people with close names join the same room and one
of them sends a message. For example:
User 1: Daniel
User 2: Daniela
When User 2 types something in the room, User 1 sees something like:
a<cite id='null-editedAt'> </cite></a></h2></td><td align="right"><h2>May
02, 2013 18:34:13</h2></td></tr></table><div id='messagenull' name =
'daniela' date="2013-05-02T18:34:13.079+0300" original_message = 'bonjour'
I hope its clear enough and of some use at the same time.