This bug was originally marked as duplicate of bug 221333, that is already resolved. This bug is still valid, so this seems to be another bug, but it might be related.
Build: NetBeans IDE Dev (Build 201302192300)
VM: Java HotSpot(TM) Client VM, 20.0-b11, Java(TM) SE Runtime Environment, 1.6.0_25-b06
OS: Windows 7
Maximum slowness yet reported was 59280 ms, average is 59280
Created attachment 131613 [details]
Created attachment 136833 [details]
org.openide.loaders.FolderChildren.createNode(FolderChildren.java:233) calls DataObject.find() under nodes children write lock