Two problem about offline message

I have the following two problems:

  1. Sometimes, I send message to the user who is offline. If he has not logined in since openfire started. he can receive the offline messages. But once he has logined in, and exits or login out.He can never receive offline message again when he is online. But he can always receive ofline broadcast message.I look over the openfire database, and find the offline message doesn’‘t been stored in the table ‘‘jiveOffline’’, so he can’'t receive the message,why this happens?

2.I have set up persistent chat room. When we discuss problems in the room, if there is some who is offline, I think the message is stored in the table ‘‘mucConversationLog’’ of openfire database. But i look over it,and there is no record in this table. The offline member can receive the chat message once he is online. But if he logins in after the openfire is restarted, he can never receive the room chat message. why? where is the message stored when chatting in the room with some room member offline?