It looks like ToT messed his 'hack' up (by making the message too long), which would break the chat for everybody else and cause the font to go large for the next few people after him, until his message disappears off the screen. (Five more people talk or wait a second) Zoneark probably wasn't using a hack at all.
While we're waiting for v9, download JVS Chat Enhancements, it has a fix for this.