JInternalFrame is not serializable in Motif & GTK L&F while it can be serialize
using other L&F's
Steps to reproduce:
1) Run the attached test TestSerializeInternalFrame
2) Change L&F to Motif or GTK using Menu "Look And Feel"
3) Click on button "Serialize InternalFrame"
4) It will throw Exception in console
5) Now try serializing in someother look and feel it will
   give message ""Successfully serialized JInternalFrame" on console

Tested on Tiger b30

Following is the exception message when serializing JInternalFrame under Motif
----------------------------------------------
Failed serializing javax.swing.JInternalFrame
java.io.NotSerializableException: javax.swing.JMenuItem$MenuItemPropertyChangeListener
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1072)
at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1366)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1338)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1281)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1070)
at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1242)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1066)
at java.io.ObjectOutputStream.access$100(ObjectOutputStream.java:135)
at java.io.ObjectOutputStream$PutFieldImpl.writeFields(ObjectOutputStream.java:1509)
at java.io.ObjectOutputStream.writeFields(ObjectOutputStream.java:418)
at java.awt.Container.writeObject(Container.java:3452)
at sun.reflect.GeneratedMethodAccessor9.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:489)
at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:902)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1330)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1281)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1070)
at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1366)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1338)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1281)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1070)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:291)
at java.beans.PropertyChangeSupport.writeObject(PropertyChangeSupport.java:427)
at sun.reflect.GeneratedMethodAccessor14.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:489)
at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:902)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1330)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1281)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1070)
at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1366)
at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:380)
at java.awt.Component.writeObject(Component.java:7363)
at sun.reflect.GeneratedMethodAccessor8.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:489)
at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:902)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1330)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1281)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1070)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:291)
at SerializeTest.serializeObject(SerializeTest.java:152)
at SerializeTest.main(SerializeTest.java:140)