diff --git a/MUNGA_L4/L4STEAMTRANSPORT.cpp b/MUNGA_L4/L4STEAMTRANSPORT.cpp
index 6e38734..ba4c55a 100644
--- a/MUNGA_L4/L4STEAMTRANSPORT.cpp
+++ b/MUNGA_L4/L4STEAMTRANSPORT.cpp
@@ -157,10 +157,13 @@ namespace
 	}
 
 	//---------------------------------------------------------------
-	// Status-changed callback (fires inside SteamAPI_RunCallbacks on
-	// the game thread): accept incoming, queue connected, mark drops
+	// Status-changed handler (fires inside SteamAPI_RunCallbacks on
+	// the game thread): accept incoming, queue connected, mark drops.
+	// Registered through the CCallback dispatcher below - the
+	// config-value function pointer is NOT dispatched by the steam_api
+	// flavor of the library (Valve's own example uses STEAM_CALLBACK).
 	//---------------------------------------------------------------
-	void __cdecl
+	void
 		OnConnectionStatusChanged(SteamNetConnectionStatusChangedCallback_t *status)
 	{
 		switch (status->m_info.m_eState)
@@ -219,6 +222,25 @@ namespace
 		}
 	}
 
+	//---------------------------------------------------------------
+	// The callback listener: constructed after SteamAPI_Init so the
+	// CCallback registration lands in a live callback manager
+	//---------------------------------------------------------------
+	class SteamTransportCallbacks
+	{
+	public:
+		STEAM_CALLBACK(SteamTransportCallbacks, OnStatusChanged,
+			SteamNetConnectionStatusChangedCallback_t);
+	};
+
+	void SteamTransportCallbacks::OnStatusChanged(
+		SteamNetConnectionStatusChangedCallback_t *status)
+	{
+		OnConnectionStatusChanged(status);
+	}
+
+	SteamTransportCallbacks *gCallbacks = NULL;
+
 	//---------------------------------------------------------------
 	// The transport
 	//---------------------------------------------------------------
@@ -306,11 +328,6 @@ namespace
 				<< inet_ntoa(remote->sin_addr) << ":" << ntohs(remote->sin_port)
 				<< " (fake port " << fake_port << ")...\n" << std::flush;
 
-			SteamNetworkingConfigValue_t option;
-			option.SetPtr(
-				k_ESteamNetworkingConfig_Callback_ConnectionStatusChanged,
-				(void *) &OnConnectionStatusChanged);
-
 			SteamNetworkingIPAddr target;
 			target.Clear();
 			target.SetIPv4(remote_fake_ip, fake_port);
@@ -323,7 +340,7 @@ namespace
 			{
 				++attempt;
 				HSteamNetConnection handle =
-					SteamNetworkingSockets()->ConnectByIPAddress(target, 1, &option);
+					SteamNetworkingSockets()->ConnectByIPAddress(target, 0, NULL);
 				if (handle == k_HSteamNetConnection_Invalid)
 				{
 					DEBUG_STREAM << "SteamNetTransport: ConnectByIPAddress refused the call\n" << std::flush;
@@ -419,13 +436,8 @@ namespace
 				<< local_port << " (fake port " << gLocalFakePorts[index]
 				<< ")...\n" << std::flush;
 
-			SteamNetworkingConfigValue_t option;
-			option.SetPtr(
-				k_ESteamNetworkingConfig_Callback_ConnectionStatusChanged,
-				(void *) &OnConnectionStatusChanged);
-
 			HSteamListenSocket handle =
-				SteamNetworkingSockets()->CreateListenSocketP2PFakeIP(index, 1, &option);
+				SteamNetworkingSockets()->CreateListenSocketP2PFakeIP(index, 0, NULL);
 			if (handle == k_HSteamListenSocket_Invalid)
 			{
 				return InvalidConnection;
@@ -615,6 +627,12 @@ Logical
 		return False;
 	}
 
+	// connection status arrives through the CCallback dispatcher
+	if (gCallbacks == NULL)
+	{
+		gCallbacks = new SteamTransportCallbacks;
+	}
+
 	SteamNetworkingUtils()->InitRelayNetworkAccess();
 
 	if (!SteamNetworkingSockets()->BeginAsyncRequestFakeIP(2))
@@ -664,6 +682,63 @@ Logical
 
 	gSteamReady = True;
 	NetTransport_Set(&gSteamTransport);
+
+	//
+	// dev: RP412STEAMSELFTEST=1 loops a connection back to ourselves,
+	// proving the listen/accept/connect/send/receive machinery (and
+	// the status-callback dispatch) without a second machine
+	//
+	const char *self_test = getenv("RP412STEAMSELFTEST");
+	if (self_test != NULL && atoi(self_test) != 0)
+	{
+		DEBUG_STREAM << "SteamNetTransport: SELF TEST starting\n" << std::flush;
+		SteamNetTransport_RegisterPeer(
+			gLocalFakeAddressString, gLocalFakePorts[0], gLocalFakePorts[1]);
+
+		NetTransport *transport = &gSteamTransport;
+		NetTransport::Connection listener = transport->Listen(1501, 1);
+
+		SOCKADDR_IN self_address;
+		transport->Resolve(gLocalFakeAddressString, &self_address);
+		self_address.sin_port = htons(1501);
+		NetTransport::Connection outgoing = transport->Connect(&self_address, 0);
+
+		NetTransport::Connection incoming = NetTransport::InvalidConnection;
+		DWORD accept_deadline = GetTickCount() + 10 * 1000;
+		while (incoming == NetTransport::InvalidConnection &&
+			(LONG)(GetTickCount() - accept_deadline) < 0)
+		{
+			incoming = transport->Accept(listener);
+			Sleep(50);
+		}
+
+		Logical ok = False;
+		if (outgoing != NetTransport::InvalidConnection &&
+			incoming != NetTransport::InvalidConnection)
+		{
+			transport->Send(outgoing, "PING", 4);
+			char buffer[16];
+			DWORD recv_deadline = GetTickCount() + 5 * 1000;
+			while ((LONG)(GetTickCount() - recv_deadline) < 0)
+			{
+				if (transport->Receive(incoming, buffer, sizeof(buffer)) == 4)
+				{
+					ok = (memcmp(buffer, "PING", 4) == 0);
+					break;
+				}
+				Sleep(25);
+			}
+		}
+		DEBUG_STREAM << "SteamNetTransport: SELF TEST "
+			<< (ok ? "PASSED" : "FAILED")
+			<< " (out " << (outgoing != NetTransport::InvalidConnection)
+			<< ", in " << (incoming != NetTransport::InvalidConnection)
+			<< ")\n" << std::flush;
+
+		// leave the session pristine for the real race
+		gSteamTransport.Cleanup();
+		gPeerCount = 0;
+	}
 	return True;
 }