diff --git a/LightAPRS-pico-balloon/LightAPRS-pico-balloon.ino b/LightAPRS-pico-balloon/LightAPRS-pico-balloon.ino
index 0b59032..bdd11ae 100644
--- a/LightAPRS-pico-balloon/LightAPRS-pico-balloon.ino
+++ b/LightAPRS-pico-balloon/LightAPRS-pico-balloon.ino
@@ -41,7 +41,7 @@ char  Symbol='O'; // '/O' for balloon, '/>' for car, for more info : http://www.
 bool  alternateSymbolTable = false ; //false = '/' , true = '\'
 
 char comment[50] = "http://www.lightaprs.com"; // Max 50 char
-char StatusMessage[50] = "LightAPRS by TA9OHC & TA2MUN";
+char StatusMessage[50] = "LightAPRS by TA2NHP & TA2MUN";
 //*****************************************************************************
 
 
@@ -120,6 +120,8 @@ void setup() {
   APRS_setPath2("WIDE2", Wide2);
   APRS_useAlternateSymbolTable(alternateSymbolTable); 
   APRS_setSymbol(Symbol);
+  //increase following value (for example to 500UL) if you experience packet loss/decode issues. 
+  APRS_setPreamble(350UL);  
   APRS_setPathSize(pathSize);
   AprsPinInput;
   
@@ -386,7 +388,19 @@ void updateTelemetry() {
   telemetry_buff[7] = '/';
   telemetry_buff[8] = 'A';
   telemetry_buff[9] = '=';
-  sprintf(telemetry_buff + 10, "%06lu", (long)gps.altitude.feet());
+  //sprintf(telemetry_buff + 10, "%06lu", (long)gps.altitude.feet());
+
+  //fixing negative altitude values causing display bug on aprs.fi
+  float tempAltitude = gps.altitude.feet();
+
+  if (tempAltitude>0){
+    //for positive values
+    sprintf(telemetry_buff + 10, "%06lu", (long)tempAltitude);
+  } else{
+    //for negative values
+    sprintf(telemetry_buff + 10, "%06d", (long)tempAltitude);
+    } 
+  
   telemetry_buff[16] = ' ';
   sprintf(telemetry_buff + 17, "%03d", TxCount);
   telemetry_buff[20] = 'T';
diff --git a/libraries/LightAPRS_Geofence/GEOFENCE.cpp b/libraries/LightAPRS_Geofence/GEOFENCE.cpp
index fb0f479..3e2b97a 100755
--- a/libraries/LightAPRS_Geofence/GEOFENCE.cpp
+++ b/libraries/LightAPRS_Geofence/GEOFENCE.cpp
@@ -101,10 +101,11 @@ int32_t pointInPolygonF(int32_t polyCorners, float * polygon, float latitude, fl
 						Indonesia			144.390
 						Malaysia			144.390
 		
-	NO AIRBORNE APRS:
-						France
+	NO AIRBORNE APRS:											
 						Latvia
+						North Korea
 						United Kingdom
+						Yemen
 	
 	Expected input FLOAT for latitude and longitude as in GPS_UBX_latitude_Float and GPS_UBX_longitude_Float.
 */
@@ -120,6 +121,7 @@ void GEOFENCE_position(float latitude, float longitude)
 		{
 			if(pointInPolygonF(9, UKF, latitude, longitude) == 1)				{GEOFENCE_no_tx = 1;GEOFENCE_APRS_frequency = 144800000;}
 			else if(pointInPolygonF(10, LatviaF, latitude, longitude) == 1)		{GEOFENCE_no_tx = 1;GEOFENCE_APRS_frequency = 144800000;}
+			else if(pointInPolygonF(5, YemenF, latitude, longitude) == 1)		{GEOFENCE_no_tx = 1;GEOFENCE_APRS_frequency = 144800000;}
 			else																{GEOFENCE_no_tx = 0; GEOFENCE_APRS_frequency = 144800000;}
 		}
 		
@@ -158,9 +160,10 @@ void GEOFENCE_position(float latitude, float longitude)
 		
 		// S 1/2
 		if(latitude > 19.2)
-		{
-			if(pointInPolygonF(12, ChinaF, latitude, longitude) == 1)			{GEOFENCE_no_tx = 0; GEOFENCE_APRS_frequency = 144640000;}
-			else if(pointInPolygonF(7, JapanF, latitude, longitude) == 1)		{GEOFENCE_no_tx = 0; GEOFENCE_APRS_frequency = 144660000;}
+		{	
+			if(pointInPolygonF(6, North_KoreaF, latitude, longitude) == 1)		{GEOFENCE_no_tx = 1; GEOFENCE_APRS_frequency = 144620000;}	
+			else if(pointInPolygonF(12, ChinaF, latitude, longitude) == 1)		{GEOFENCE_no_tx = 0; GEOFENCE_APRS_frequency = 144640000;}
+			else if(pointInPolygonF(7, JapanF, latitude, longitude) == 1)		{GEOFENCE_no_tx = 0; GEOFENCE_APRS_frequency = 144660000;}		
 			else if(pointInPolygonF(5, South_KoreaF, latitude, longitude) == 1)	{GEOFENCE_no_tx = 0; GEOFENCE_APRS_frequency = 144620000;}
 			else if(pointInPolygonF(5, ThailandF, latitude, longitude) == 1)	{GEOFENCE_no_tx = 0; GEOFENCE_APRS_frequency = 145525000;}
 			else																{GEOFENCE_no_tx = 0; GEOFENCE_APRS_frequency = 144800000;}
diff --git a/libraries/LightAPRS_Geofence/GEOFENCE.h b/libraries/LightAPRS_Geofence/GEOFENCE.h
index 2fb9503..4864810 100755
--- a/libraries/LightAPRS_Geofence/GEOFENCE.h
+++ b/libraries/LightAPRS_Geofence/GEOFENCE.h
@@ -114,6 +114,15 @@ static float RomaniaF[] = {
 	27.12520,		47.95310
 };
 
+static float North_KoreaF[] = {
+	130.14189, 4321627,
+	124.03574, 39.8949,
+	125.18292, 37.39202,
+	128.47240, 38.66888,
+	130.69478, 42.3274,
+	130.14189, 43.21627
+};
+
 static float South_KoreaF[] = {
 	132.17653,		41.01310,
 	124.61794,		36.70367,
@@ -152,6 +161,13 @@ static float VenezuelaF[] = {
 	-66.65410,		0.18680
 };
 
+static float YemenF[] = {
+	52.20302, 19.48287,
+	41.92009, 17.42198,
+	43.59620, 12.27820,
+	53.68201, 15.80024,
+	52.20302, 19.48287
+};
 
 // VARIABLES
 extern uint32_t GEOFENCE_APRS_frequency;