diff --git a/RFControl.cpp b/RFControl.cpp
index 2bb46e4..49badb0 100644
--- a/RFControl.cpp
+++ b/RFControl.cpp
@@ -104,7 +104,7 @@ bool RFControl::existNewDuration(){
 }
 
 bool probablyFooter(unsigned int duration) {
-  return duration >= MIN_FOOTER_LENGTH; 
+  return duration >= MIN_FOOTER_LENGTH && ((int)duration >0); 
 }
 
 bool matchesFooter(unsigned int duration) {
@@ -117,6 +117,9 @@ void startRecording(unsigned int duration) {
   printf(" => start recoding");
   #endif
   footer_length = duration;
+  #ifdef RF_CONTROL_SIMULATE_ARDUINO
+  printf(" footer =  %u",duration);
+  #endif
   data_end[0] = 0;
   data_end[1] = 0;
   data_end[2] = 0;
@@ -164,7 +167,14 @@ void recording(unsigned int duration, int package) {
   else if (duration < 100000)
     printf(" duration=%i", duration);
 #endif
-  if (matchesFooter(duration)) //test for footer (+-25%).
+  if ((int)duration < 0){
+    
+#ifdef RF_CONTROL_SIMULATE_ARDUINO
+    printf("invalid duration=%i", duration);
+#endif
+	RFControl::startReceiving(interruptPin);
+
+  }else  if (matchesFooter(duration)) //test for footer (+-25%).
   {
     //Package is complete!!!!
     timings[data_end[package]] = duration;