Reconnection Error Stream Management Smack

Question

i discovered a really big problem (probably mine?) about the XMPP reconnection process in smack library v4.1.5 (Android) and openfire v4.0.1. I activated the stream management on the client in this way:

XMPPTCPConnection.setUseStreamManagementDefault(true);
XMPPTCPConnection.setUseStreamManagementResumptionDefault(true);

and activated the automatic reconnection in this way:

ReconnectionManager.getInstanceFor(this.xmppConnection).enableAutomaticReconnection();

After the first successfull connection and login, when the internet connection goes down and the reconnection process starts I get the following error:

W/AbstractXMPPConnection: Connection closed with error
    org.jivesoftware.smack.XMPPException$StreamErrorException: conflict You can read more about the meaning of this stream error at http://xmpp.org/rfcs/rfc6120.html#streams-error-conditions
    <stream:error><conflict xmlns='urn:ietf:params:xml:ns:xmpp-streams'/></stream:error>
at org.jivesoftware.smack.tcp.XMPPTCPConnection$PacketReader.parsePackets(XMPPTCPConnection.java:1003)
at org.jivesoftware.smack.tcp.XMPPTCPConnection$PacketReader.access$300(XMPPTCPConnection.java:944)
at org.jivesoftware.smack.tcp.XMPPTCPConnection$PacketReader$1.run(XMPPTCPConnection.java:959)

The reconnection manager connects and authenticates very well but then I receive the previous error! I tried to change the resource also but nothing, it doesn't work! Someone could help me in understanding what is wrong?