JInternalFrame window button menu has close button disabled with DISPOSE_ON_CLOSE option when motif is the L&F.

Steps to reproduce:
1) Compile and run the attached code.
2) Click on the window menu button (Left Top of the title bar)
3) Notice that the close button on the drop down is disabled.
4) This close button of the drop down is enabled on other L&F.

This was observed on the PIT request of 29th Aug 2003
The Java version for solaris is:
java version "swing-jcg-sparc-01-2003-08-29-int.tiger"
Java(TM) 2 Runtime Environment, Standard Edition (build swing-jcg-sparc-01-2003-08-29-int.tiger)