When I try to start a conversation with a contact in specific, just one in particular, the Spark is locked and unresponsive, the only way to close it is ending the process from the windows task manager.
Also if the same contact, try to write from the other side, the client does not receive the message.
I have the version 2.6.3, windows 7, 32 bit, with openfire.
May be due to this problem? Only about 1 contact with everyone else works normally