Getting Null Pointer Exception when displaying message for a TrayIcon.
I reproduced this with Opensolaris 2009.06 with Jdk7 b60 build. Works fine on jdk6 u14.

Steps To reproduce:

1.Run the attached jar file.
   java -jar awt_demo.jar
2.Choose tab "TrayIconDemo"
3. Enter an ImagePath , then click the "Initialize the TrayIcon" button
4. Select the Trayicon instance from the "Select a TrayIcon" ComboBox and click "Add Icon " button
5. Enter a message and enter a caption
6. Enter a message type (can be any.. ex ERROR) and click Display Message button
7. You can see the Display Message for the trayicon. Close the Display Message
8. Now click the Display Message button again with the same message type (ex ERROR)
9. If you see the Exception the bug is reproduced.

The stack trace is as follows:
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at sun.awt.X11.XEmbeddedFramePeer.getAbsoluteX(XEmbeddedFramePeer.java:279)
at sun.awt.X11.XBaseWindow.getAbsoluteX(XBaseWindow.java:1170)
at sun.awt.X11.XBaseWindow.toOtherWindow(XBaseWindow.java:746)
at sun.awt.X11.XBaseWindow.toGlobal(XBaseWindow.java:784)
at sun.awt.X11.XEmbeddedFramePeer.getLocationOnScreen(XEmbeddedFramePeer.java:193)
at java.awt.Component.getLocationOnScreen_NoTreeLock(Component.java:1914)
at java.awt.Component.getLocationOnScreen(Component.java:1892)
at sun.awt.X11.InfoWindow$Balloon$3.run(InfoWindow.java:399)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:235)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:603)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:286)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:191)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:186)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:178)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:139)
Also reproducible on Ubuntu 8.04