diff --git a/src/main/java/org/gcube/portlets/widgets/workspaceuploader/client/uploader/dragdrop/MultipleDNDUpload.java b/src/main/java/org/gcube/portlets/widgets/workspaceuploader/client/uploader/dragdrop/MultipleDNDUpload.java
index 4c0f73c..dbf2113 100644
--- a/src/main/java/org/gcube/portlets/widgets/workspaceuploader/client/uploader/dragdrop/MultipleDNDUpload.java
+++ b/src/main/java/org/gcube/portlets/widgets/workspaceuploader/client/uploader/dragdrop/MultipleDNDUpload.java
@@ -58,6 +58,18 @@ public class MultipleDNDUpload extends LayoutPanel implements
 		// ScriptInjector.fromUrl("workspaceuploader/dndhtmlfileupload.js")
 		// .setWindow(ScriptInjector.TOP_WINDOW).inject();
 	}
+	
+	/* (non-Javadoc)
+	 * @see com.google.gwt.user.client.ui.LayoutPanel#onAttach()
+	 */
+	@Override
+	protected void onAttach() {
+		super.onAttach();
+		
+		if(onlyChild!=null){
+			onlyChild.getElement().setId("drop_target_only_child");
+		}
+	}
 
 	/**
 	 * Adds the unique container. You must add a unique panel in order to DND
@@ -75,7 +87,7 @@ public class MultipleDNDUpload extends LayoutPanel implements
 			}
 		}
 		onlyChild = w;
-		onlyChild.getElement().setId("drop_target_only_child");
+//		onlyChild.getElement().setId("drop_target_only_child");
 		super.add(onlyChild);
 	}
 
@@ -100,7 +112,12 @@ public class MultipleDNDUpload extends LayoutPanel implements
 	 */
 	public void setVisibleOnlyChild(boolean bool) {
 		if (onlyChild != null) {
-			onlyChild.setVisible(bool);
+			GWT.log("setVisibleOnlyChild: "+bool );
+//			onlyChild.setVisible(bool);
+			if(bool)
+				onlyChild.getElement().getStyle().setOpacity(1.0);
+			else
+				onlyChild.getElement().getStyle().setOpacity(0.2);
 		}
 	}
 
@@ -267,6 +284,7 @@ public class MultipleDNDUpload extends LayoutPanel implements
 		drop.className = "over-false";
 		$wnd.$('#drop_target_inner')[0].className = "";
 		$wnd.$('#drop_target_outer')[0].style.display = "none";
+//		$wnd.$('#drop_target_only_child')[0].style.display = "";
 		instance.@org.gcube.portlets.widgets.workspaceuploader.client.uploader.dragdrop.MultipleDNDUpload::setVisibleOnlyChild(Z)(true);
 	}-*/;
 
@@ -336,6 +354,7 @@ public class MultipleDNDUpload extends LayoutPanel implements
 			console.log("before load");
 			var drop = $wnd.$('#drop_target')[0];
 			$wnd.$('#drop_target_outer')[0].style.display = "none";
+			
 			console.log("drop is " + drop);
 
 			function cancel(e) {
@@ -384,7 +403,9 @@ public class MultipleDNDUpload extends LayoutPanel implements
 						console.log('dragenter');
 						drop.className = "over-true";
 						$wnd.$('#drop_target_inner')[0].className = "";
+//						$wnd.$('#drop_target_only_child')[0].style.display = "none";
 						instance.@org.gcube.portlets.widgets.workspaceuploader.client.uploader.dragdrop.MultipleDNDUpload::setVisibleOnlyChild(Z)(false);
+						
 						e.preventDefault();
 						if (containsFiles(e)) {
 							console.log("The drag event contains files");
@@ -406,6 +427,7 @@ public class MultipleDNDUpload extends LayoutPanel implements
 						drop.className = "over-false";
 						$wnd.$('#drop_target_inner')[0].className = "";
 						$wnd.$('#drop_target_outer')[0].style.display = "none";
+//						$wnd.$('#drop_target_only_child')[0].style.display = "";
 						instance.@org.gcube.portlets.widgets.workspaceuploader.client.uploader.dragdrop.MultipleDNDUpload::setVisibleOnlyChild(Z)(true);
 						instance.@org.gcube.portlets.widgets.workspaceuploader.client.uploader.dragdrop.MultipleDNDUpload::setLimitExceeded(Z)(false);
 					});
@@ -418,6 +440,7 @@ public class MultipleDNDUpload extends LayoutPanel implements
 				console.log('dragover');
 				drop.className = "over-true";
 				$wnd.$('#drop_target_outer')[0].style.display = "inline";
+//				$wnd.$('#drop_target_only_child')[0].style.display = "none";
 			});
 
 			addEventHandler(