Application crashes with mouse-click and key-press on PopupMenu in Solaris & Linux.

* Compile and Run PopupMenuTest.java
* Right click on label so as to show popup menu
* Move mouse over first MenuItem, so as to expand it and show its second level
* Click on first MenuItem so as to hide the second level MenuItems
* Press any arrow keys, application crashes.

Log file attached.

bash-2.05$ java PopupMenuTest
#
# An unexpected error has been detected by HotSpot Virtual Machine:
#
# SIGSEGV (0xb) at pc=0xfe1a6e24, pid=9207, tid=11
#
# Java VM: Java HotSpot(TM) Client VM (1.5.0-beta2-b41 mixed mode)
# Problematic frame:
# C [libXt.so.4+0x16e24] XtIsSubclass+0x80
#
# An error report file with more information is saved as hs_err_pid9207.log
#
# If you would like to submit a bug report, please visit:
# http://java.sun.com/webapps/bugreport/crash.jsp
#
Abort (core dumped)
bash-2.05$