diff --git a/Platform.cpp b/Platform.cpp
index a492eaf..2177d78 100644
--- a/Platform.cpp
+++ b/Platform.cpp
@@ -312,7 +312,7 @@ void Platform::ClassReport(char* className, float &lastTime)
 // should compute it for you (i.e. it won't need to be calculated at run time).
 
 // If the A->D converter has a range of 0..1023 and the measured voltage is V (between 0 and 1023)
-// then the thermistor resistance, R = V.RS/(1023 - V)
+// then the thermistor resistance, R = V.RS/(1024 - V)
 // and the temperature, T = BETA/ln(R/R_INF)
 // To get degrees celsius (instead of kelvin) add -273.15 to T
 //#define THERMISTOR_R_INFS ( THERMISTOR_25_RS*exp(-THERMISTOR_BETAS/298.15) ) // Compute in Platform constructor
@@ -321,8 +321,10 @@ void Platform::ClassReport(char* className, float &lastTime)
 
 float Platform::GetTemperature(int8_t heater)
 {
-  float r = (float)GetRawTemperature(heater);
-  return ABS_ZERO + thermistorBetas[heater]/log( (r*thermistorSeriesRs[heater]/(AD_RANGE - r))/thermistorInfRs[heater] );
+  // If the ADC reading is N then for an ideal ADC, the input voltage is at least N/(ADC_RANGE + 1) and less than (N + 1)/(ADC_RANGE + 1), times the analog reference.
+  // So we add 0.5 to to the reading to get a better estimate of the input. We don't care whether or not we get exactly zero with the thermistor disconnected.
+  float r = (float)GetRawTemperature(heater) + 0.5;
+  return ABS_ZERO + thermistorBetas[heater]/log( (r*thermistorSeriesRs[heater]/((AD_RANGE + 1) - r))/thermistorInfRs[heater] );
 }
 
 
@@ -864,9 +866,10 @@ void RepRapNetworkInputBufferReleased(void* pb)
 	reprap.GetPlatform()->GetNetwork()->InputBufferReleased(pb);
 }
 
-void RepRapNetworkHttpStateReleased(void* h)
+void RepRapNetworkConnectionError(void* h)
 {
-	reprap.GetPlatform()->GetNetwork()->HttpStateReleased(h);
+	reprap.GetPlatform()->GetNetwork()->ConnectionError(h);
+	reprap.GetWebserver()->ConnectionError();
 }
 
 // Called to put out a message via the RepRap firmware.
@@ -1053,14 +1056,19 @@ void Network::InputBufferReleased(void* pb)
 	netRingGetPointer->ReleasePbuf();
 }
 
-void Network::HttpStateReleased(void* h)
+void Network::ConnectionError(void* h)
 {
-	if(netRingGetPointer->Hs() != h)
+	// h points to an http state block that the caller is about to release, so we need to stop referring to it.
+	// The state block is usually but not always in use by the current http request being processed, in which case we abandon the current request.
+	if (netRingGetPointer != netRingAddPointer && netRingGetPointer->Hs() == h)
 	{
-		reprap.GetPlatform()->Message(HOST_MESSAGE, "Network::HttpStateReleased() - Pointers don't match!\n");
-		return;
+		netRingGetPointer->Free();
+		netRingGetPointer = netRingGetPointer->Next();
 	}
-	netRingGetPointer->ReleaseHs();
+
+	// Reset the network layer. In particular, this clears the output buffer to make sure nothing more gets sent,
+	// and sets statue to 'nothing' so that we can accept another connection attempt.
+	Reset();
 }
 
 
diff --git a/Platform.h b/Platform.h
index f8e769a..f701f88 100644
--- a/Platform.h
+++ b/Platform.h
@@ -273,7 +273,7 @@ public:
 	void Close();
 	void ReceiveInput(char* data, int length, void* pb, void* pc, void* h);
 	void InputBufferReleased(void* pb);
-	void HttpStateReleased(void* h);
+	void ConnectionError(void* h);
 	bool Active();
 	bool LinkIsUp();
 
diff --git a/Webserver.cpp b/Webserver.cpp
index e743a89..3be5036 100644
--- a/Webserver.cpp
+++ b/Webserver.cpp
@@ -711,6 +711,30 @@ void Webserver::Init()
   //platform->GetMassStorage()->Delete(platform->GetWebDir(), MESSAGE_FILE);
 }
 
+// This is called when the connection has been lost.
+// In particular, we must cancel any pending writes.
+void Webserver::ConnectionError()
+{
+	  writing = false;
+	  receivingPost = false;
+	  postSeen = false;
+	  getSeen = false;
+	  jsonPointer = -1;
+	  clientLineIsBlank = true;
+	  needToCloseClient = false;
+	  clientLinePointer = 0;
+	  clientLine[0] = 0;
+	  clientRequest[0] = 0;
+	  gotPassword = false;
+	  gcodeAvailable = false;
+	  gcodePointer = 0;
+	  InitialisePost();
+	  lastTime = platform->Time();
+	  longWait = lastTime;
+	  active = true;
+
+}
+
 void Webserver::Exit()
 {
   platform->Message(HOST_MESSAGE, "Webserver class exited.\n");
diff --git a/Webserver.h b/Webserver.h
index 8876b6f..a05575c 100644
--- a/Webserver.h
+++ b/Webserver.h
@@ -50,6 +50,7 @@ class Webserver
     void Diagnostics();
     void SetPassword(char* pw);
     void SetName(char* nm);
+    void ConnectionError();
     
   private:
   
diff --git a/network/httpd.c b/network/httpd.c
index e9c5f8a..1366463 100644
--- a/network/httpd.c
+++ b/network/httpd.c
@@ -72,7 +72,7 @@ struct http_state {
 
 void RepRapNetworkReceiveInput(char* ip, int length, void* pbuf, void* pcb, void* hs);
 void RepRapNetworkInputBufferReleased(void* pbuf);
-void RepRapNetworkHttpStateReleased(void* h);
+void RepRapNetworkConnectionError(void* h);
 void RepRapNetworkMessage(char* s);
 void RepRapNetworkAllowWriting();
 bool RepRapNetworkHasALiveClient();
@@ -86,15 +86,19 @@ static int initCount = 0;
 static void
 conn_err(void *arg, err_t err)
 {
-  struct http_state *hs;
+  // Report the error to the monitor
+  RepRapNetworkMessage("Network connection error, code ");
+  {
+	char tempBuf[10];
+	snprintf(tempBuf, sizeof(tempBuf)/sizeof(char), "%d\n", err);
+	RepRapNetworkMessage(tempBuf);
+  }
 
-  LWIP_UNUSED_ARG(err);
-
-  hs = arg;
-  mem_free(hs);
-  //RepRapNetworkHttpStateReleased(hs);
-  RepRapNetworkMessage("Network connection error.\n");
+  struct http_state *hs = arg;
+  RepRapNetworkConnectionError(hs);		// tell the higher levels about the error
+  mem_free(hs);							// release the state data
 }
+
 /*-----------------------------------------------------------------------------------*/
 
 static void