Why doesn't the entire chat room history get returned when I join the room?

Hello,

System setup:

    Server - Openfire 3.3.3

    API's - Smack, Smackx and JSJAC

    Property - xmpp.muc.history.type = all

What I am wondering is why I do not get all the chat room messages when I join the room.  I seem to only get recent ones!  For example, when I look in the database in the MUCCONVERSATIONLOG table I have 24 messages in a specific room, but when I join the room, or use MultiUserChat.nextMessage(100) to get the history, I only get 3 (the most recent, which is in the db).  Is there a time limit on the server only returning messages within a certain time frame?  Am I only getting the messages in the cache?  If so, how many messages can be stored in the cache for a specific room?  Where is the cache located and when is it cleared?  Any help would be much appreciated!

Thanks,

Josh