diff --git a/chouette-exchange-gtfs/src/main/java/fr/certu/chouette/exchange/gtfs/exporter/GtfsDataProducer.java b/chouette-exchange-gtfs/src/main/java/fr/certu/chouette/exchange/gtfs/exporter/GtfsDataProducer.java
index a4e181c6e..8fc0d8f9d 100644
--- a/chouette-exchange-gtfs/src/main/java/fr/certu/chouette/exchange/gtfs/exporter/GtfsDataProducer.java
+++ b/chouette-exchange-gtfs/src/main/java/fr/certu/chouette/exchange/gtfs/exporter/GtfsDataProducer.java
@@ -8,13 +8,14 @@
 
 package fr.certu.chouette.exchange.gtfs.exporter;
 
+import java.util.HashSet;
 import java.util.Iterator;
+import java.util.Set;
 import java.util.TimeZone;
 
-import org.apache.log4j.Logger;
-
 import lombok.Setter;
 
+import org.apache.log4j.Logger;
 
 import fr.certu.chouette.exchange.gtfs.exporter.producer.IGtfsProducer;
 import fr.certu.chouette.exchange.gtfs.exporter.report.GtfsReport;
@@ -98,6 +99,29 @@ public GtfsData produce(NeptuneData neptuneData,TimeZone timeZone, GtfsReport re
          throw new GtfsExportException(GtfsExportExceptionCode.ERROR, "missing data");
       // check if no data for one or more types 
       boolean error = false;
+      
+      // Trim references to non-existing or non-exported parent stations
+      Set<String> stationIds = new HashSet<String>();
+      for (GtfsStop station : gtfsData.getStops())
+      {
+    	  if (station.getLocationType() == GtfsStop.STATION)
+    	  {
+    		  stationIds.add(station.getStopId());
+    	  }
+      }
+      for (GtfsStop stop : gtfsData.getStops())
+      {
+    	  if (stop.getLocationType() == GtfsStop.STOP)
+    	  {
+    		  if (!stationIds.contains(stop.getParentStation()))
+    		  {
+    			  stop.setParentStation(null);
+    			  GtfsReportItem item = new GtfsReportItem(GtfsReportItem.KEY.MISSING_DATA, STATE.WARNING, "Stop", stop.getStopId(), "parentStation");
+    			  report.addItem(item);
+    		  }
+    	  }
+      }
+      
       if (gtfsData.getAgencies().isEmpty()) 
       {
          logger.error("no company for agencies.txt");
diff --git a/chouette-exchange-gtfs/src/main/java/fr/certu/chouette/exchange/gtfs/model/GtfsTime.java b/chouette-exchange-gtfs/src/main/java/fr/certu/chouette/exchange/gtfs/model/GtfsTime.java
index e82275ad6..ee22f4c7c 100644
--- a/chouette-exchange-gtfs/src/main/java/fr/certu/chouette/exchange/gtfs/model/GtfsTime.java
+++ b/chouette-exchange-gtfs/src/main/java/fr/certu/chouette/exchange/gtfs/model/GtfsTime.java
@@ -10,6 +10,7 @@
 
 import java.sql.Time;
 import java.text.MessageFormat;
+import java.util.Calendar;
 
 import lombok.Getter;
 import lombok.Setter;
@@ -59,15 +60,15 @@ public GtfsTime(Time time,boolean tomorrow)
 
 	public String toString()
 	{
-
-		long h = time.getTime()/1000;
-		long s = h%60;
-		h=h/60;
-		long m = h % 60;
-		h=h/60;
-		if (tomorrow) h+= 24;
+		// This will use default JVM timezone
+		Calendar cal = Calendar.getInstance();
+		cal.setTime(time);
+		long h = cal.get(Calendar.HOUR_OF_DAY);
+		long m = cal.get(Calendar.MINUTE);
+		long s = cal.get(Calendar.SECOND);
+		if (tomorrow)
+			h+=24;
 		return MessageFormat.format(mfHoraireHMS,h,m,s);
-
 	}
 
     public String toSeconds()