Index: utils/josm/plugins/landsat/src/landsat/DownloadLandsatTask.java
===================================================================
--- utils/josm/plugins/landsat/src/landsat/DownloadLandsatTask.java	(revision 1476)
+++ utils/josm/plugins/landsat/src/landsat/DownloadLandsatTask.java	(revision 1477)
@@ -51,6 +51,11 @@
 	}
 
+	public void setEnabled(boolean b) {
+		checkBox.setEnabled(b); 
+	}
+
 	public String getPreferencesSuffix() {
 		return "landsat";
 	}
+
 }
Index: utils/josm/plugins/landsat/src/landsat/LandsatPlugin.java
===================================================================
--- utils/josm/plugins/landsat/src/landsat/LandsatPlugin.java	(revision 1476)
+++ utils/josm/plugins/landsat/src/landsat/LandsatPlugin.java	(revision 1477)
@@ -3,9 +3,25 @@
 import org.openstreetmap.josm.Main;
 import org.openstreetmap.josm.plugins.Plugin;
+import org.openstreetmap.josm.gui.MapFrame;
+
+// NW 151006 only add the landsat task when the map frame is initialised with
+// data.
 
 public class LandsatPlugin extends Plugin {
 
+	DownloadLandsatTask task;
+
 	public LandsatPlugin() {
-		Main.main.menu.download.downloadTasks.add(new DownloadLandsatTask());
+		task = new DownloadLandsatTask();
+		task.setEnabled(false);
+		Main.main.menu.download.downloadTasks.add(task);
+	}
+
+	public void mapFrameInitialized(MapFrame oldFrame, MapFrame newFrame) {
+		if(oldFrame==null && newFrame!=null) { 
+			task.setEnabled(true);
+		} else if (oldFrame!=null && newFrame==null ) {
+			task.setEnabled(false);
+		}
 	}
 }