This bug was originally marked as duplicate of bug 118562, that is already resolved. This bug is still valid, so this seems to be another bug, but it might be related.

Build: NetBeans IDE 6.9 (Build 201007282301)
VM: Java HotSpot(TM) Client VM, 16.3-b01, Java(TM) SE Runtime Environment, 1.6.0_20-b02
OS: Linux

User Comments:
GUEST: 1. Made panel with some controls
2. Put this panel in another panel
3. Tried to layout it relative to button at the bottom, but get this error

(I'm not native english speaker, so sorry if that doesn't make any sense)

mcseemz: In form view I chose Palette>Choose Bean, then entered the class of my JPanel
Panel showed but with defects in drawing (not all controls drawed completely)
after placing panel it cannot be relocated, as after drag-and-drop it returns to the original placement




Stacktrace: 
java.lang.NullPointerException
   at org.netbeans.modules.form.layoutdesign.LayoutModel.removeInterval(LayoutModel.java:337)
   at org.netbeans.modules.form.layoutdesign.LayoutDesigner.intervalRemoved(LayoutDesigner.java:3814)
   at org.netbeans.modules.form.layoutdesign.LayoutDesigner.layoutChanged(LayoutDesigner.java:2286)
   at org.netbeans.modules.form.layoutdesign.LayoutDesigner.access$100(LayoutDesigner.java:60)
   at org.netbeans.modules.form.layoutdesign.LayoutDesigner$Listener.layoutChanged(LayoutDesigner.java:2252)
   at org.netbeans.modules.form.layoutdesign.LayoutModel.fireEvent(LayoutModel.java:808)