Index: applications/editors/josm/plugins/DirectUpload/src/org/openstreetmap/josm/plugins/DirectUpload/UploadDataGuiPlugin.java
===================================================================
--- applications/editors/josm/plugins/DirectUpload/src/org/openstreetmap/josm/plugins/DirectUpload/UploadDataGuiPlugin.java	(revision 20877)
+++ applications/editors/josm/plugins/DirectUpload/src/org/openstreetmap/josm/plugins/DirectUpload/UploadDataGuiPlugin.java	(revision 20880)
@@ -11,4 +11,5 @@
 import java.awt.event.ActionEvent;
 import java.awt.event.KeyEvent;
+import java.util.List;
 
 import org.openstreetmap.josm.Main;
@@ -44,5 +45,6 @@
         @Override
 		protected void updateEnabledState() {
-            if(Main.map == null
+           	// enable button if there is "one active GpxLayer" or "exactly one GpxLayer in the list of all layers available"
+           	if(Main.map == null
                     || Main.map.mapView == null
                     || Main.map.mapView.getActiveLayer() == null
@@ -53,5 +55,11 @@
             }
 
-		}		
+            if(Main.map != null && Main.map.mapView.getNumLayers() > 1) {
+                List<GpxLayer> list = Main.map.mapView.getLayersOfType(GpxLayer.class);
+                if (list.size() == 1)
+                    setEnabled(true);
+            }
+
+        }		
     }
 }