--- openide.nodes/src/org/openide/util/actions/NodeAction.java	
+++ openide.nodes/src/org/openide/util/actions/NodeAction.java	
@@ -611,9 +611,15 @@ 
         }
 
         public void resultChanged(LookupEvent ev) {
-            boolean old = enabled;
+            final boolean old = enabled;
             enabled = delegate.enable(nodes());
-            support.firePropertyChange(PROP_ENABLED, old, enabled);
+            Mutex.EVENT.readAccess(new Runnable() {
+
+                @Override
+                public void run () {
+                    support.firePropertyChange(PROP_ENABLED, old, enabled);
+                }
+            });
         }
 
         public JMenuItem getMenuPresenter() {