[Biker_GA]

OK.. Open vbchat.php and look for:

// Get All Chat Messege's If Any
		$Get_Chat_MSG = $DB->query("select u.*,m.* from ".TABLE_PREFIX."vbchat_store m left join ".TABLE_PREFIX."user u on (u.userid = m.s_postby) where m.s_forroom = '{$bbuserinfo['vbchat_pref_in_room']}' order by m.s_postime desc limit 0,15");

If I recall, the number at the end of the last line defines the number of chat messages to remain in the screen. Again, been a long time since I've played with this one, so I'm not entirely positive that's the line.