Тут хорошо бы нетлог, плюс ещё понять как именно идет инициализируется передачи файла, в XMPP три разных варианта передачи файлов.
<iq xml:lang='en' to='first_user@xmpp.jp/Miranda' from='second_user@xmpp.jp/Miranda' type='error' id='mir_804'><error code='404' type='cancel'><item-not-found xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/></error></iq>
[19:57:16 17D24] [JABBER_1] recvResult = 210
[19:57:16 17D24] [JABBER_1] bytesParsed = 210
[19:57:16 18834] [JABBER_1] NetlibBindAcceptThread (00000000000008E0): accept V4 failed (10038)
[19:57:16 18834] [JABBER_1] NetlibBindAcceptThread: (FFFFFFFFFFFFFFFF) thread for port 53163 closed
[19:57:16 18B80] [JABBER_1] (4294967295) Port 53163 closed for incoming connections
[19:57:16 18B80] [JABBER_1] File transfer complete with error
[19:57:16 18B80] [JABBER_1] Destroying file transfer session 0000000002BCB400
[19:57:16 17D24] SSL failure recieving data (10054)
[19:57:16 17D24] [JABBER_1] Netlib_Recv() failed, error=10054
[19:57:16 17D24] [JABBER_1] recvResult = 0
[19:57:16 17D24] [JABBER_1] m_iDesiredStatus reset to (40072,40072) => 40071
[19:57:16 17D24] [JABBER_1] leaving worker thread
[19:57:16 17D24] [JABBER_1] Thread ended: type=0 server='xmpp.jp'
[19:57:16 17D24] [JABBER_1] (00000000026DF520:2392) Connection closed internal
[19:57:16 17D24] [JABBER_1] (00000000026DF520:4294967295) Connection closed
[19:57:16 17D24] [JABBER_1] Exiting ServerThread