diff --git a/java.project/src/org/netbeans/spi/java/project/support/ui/PackageViewChildren.java b/java.project/src/org/netbeans/spi/java/project/support/ui/PackageViewChildren.java
--- a/java.project/src/org/netbeans/spi/java/project/support/ui/PackageViewChildren.java
+++ b/java.project/src/org/netbeans/spi/java/project/support/ui/PackageViewChildren.java
@@ -296,8 +296,7 @@
         }
         
         while ( FileUtil.isParentOf( root, parent ) ) {
-            PackageNode n = get( parent );
-            if ( n != null && n.isLeaf() ) {
+            if (isEmpty(parent)) {
                 // System.out.println("Cleaning " + parent);
                 remove( parent );
             }
@@ -354,6 +353,16 @@
         }
     }
 
+    private boolean isEmpty( FileObject fo) {
+        String path = FileUtil.getRelativePath( root, fo );
+        assert path != null : "Asking for wrong folder" + fo;
+        Object o = names2nodes.get( path );
+        if (isNodeCreated(o)) {
+            return ((Node)o).isLeaf();
+        }
+        return o == NODE_NOT_CREATED_EMPTY;
+    }
+
     private PackageNode get( FileObject fo ) {
         String path = FileUtil.getRelativePath( root, fo );        
         assert path != null : "Asking for wrong folder" + fo;
@@ -394,7 +403,7 @@
 
     public void fileChanged( FileEvent fe ) {} 
 
-    public void fileFolderCreated(final FileEvent fe ) {
+    public void fileFolderCreated(final FileEvent fe ) {     
         FileObject fo = fe.getFile();        
         if ( FileUtil.isParentOf( root, fo ) && isVisible( root, fo ) ) {
             if (ProjectManager.mutex().isReadAccess() || ProjectManager.mutex().isWriteAccess()) {
@@ -405,9 +414,11 @@
                 });
                 return;
             }
-            cleanEmptyKeys( fo );                
+            synchronized (names2nodes) {
+                cleanEmptyKeys( fo );
 //            add( fo, false);
-            findNonExcludedPackages( fo );
+                findNonExcludedPackages( fo );
+            }
             refreshKeysAsync();
         }
     }