diff --git a/o.n.swing.outline/src/org/netbeans/swing/outline/Outline.java b/o.n.swing.outline/src/org/netbeans/swing/outline/Outline.java
--- a/o.n.swing.outline/src/org/netbeans/swing/outline/Outline.java
+++ b/o.n.swing.outline/src/org/netbeans/swing/outline/Outline.java
@@ -707,6 +707,10 @@
         boolean isTreeColumn = isTreeColumnIndex(column);
         if (isTreeColumn && e instanceof MouseEvent) {
             MouseEvent me = (MouseEvent) e;
+            // It may be a request to check/uncheck a check-box
+            if (checkAt(row, column, me)) {
+                return false;
+            }
             TreePath path = getLayoutCache().getPathForRow(convertRowIndexToModel(row));
             if (!getOutlineModel().isLeaf(path.getLastPathComponent())) {
                 int handleWidth = DefaultOutlineCellRenderer.getExpansionHandleWidth();
@@ -764,10 +768,6 @@
                     return false;
                 }
             }
-            // It may be a request to check/uncheck a check-box
-            if (checkAt(row, column, me)) {
-                return false;
-            }
         }
             
         boolean res = false;
@@ -814,7 +814,7 @@
         return false;
     }
 
-    private boolean checkAt(int row, int column, MouseEvent me) {
+    protected final boolean checkAt(int row, int column, MouseEvent me) {
         RenderDataProvider render = getRenderDataProvider();
         TableCellRenderer tcr = getDefaultRenderer(Object.class);
         if (render instanceof CheckRenderDataProvider && tcr instanceof DefaultOutlineCellRenderer) {
@@ -838,8 +838,7 @@
                     int chEnd = chStart + chWidth;
                     //TODO: Translate x/y to position of column if non-0
 
-                    chBoxPosition = (me.getX() > ins.left && me.getX() >= chStart && me.getX() <= chEnd) &&
-                                    me.getClickCount() == 1;
+                    chBoxPosition = (me.getX() > ins.left && me.getX() >= chStart && me.getX() <= chEnd);
                 }
                 if (chBoxPosition) {
                     Boolean selected = crender.isSelected(value);
diff --git a/openide.explorer/src/org/openide/explorer/view/OutlineView.java b/openide.explorer/src/org/openide/explorer/view/OutlineView.java
--- a/openide.explorer/src/org/openide/explorer/view/OutlineView.java
+++ b/openide.explorer/src/org/openide/explorer/view/OutlineView.java
@@ -1910,6 +1910,9 @@
             boolean actionPerformed = false;
             boolean isTreeColumn = convertColumnIndexToModel(column) == 0;
             if (isTreeColumn && row != -1 && e instanceof MouseEvent && SwingUtilities.isLeftMouseButton ((MouseEvent) e)) {
+                if (checkAt(row, column, (MouseEvent) e)) {
+                    return false;
+                }
                 int clickCount = ((MouseEvent) e).getClickCount();
                 if (clickCount > 1) {
                     // Default action.