Sending message user offline

vesrion of openfire : Openfire 4.2.3
i have two user A and B
A is offline
B send a message to A then i change B to Offline
I connect with the user A.
Only one mesage is receive
And if take a look to the datatable ofMessageArchive the message is in the datatable but if i take a look in datatable ofConParticipant there is only one line (one participant)
Openfire 4.2.3
Help please?