Problematic Thread: prio=1, An unexpected exception has been detected

I got the following crash when clicking on the Lines tab in Java2Demo,
but it is a random error. There is no definite sequence of actions
which reproduces the bug, but I have seen it happen several times.
Since the error is in native code outside the VM, it is not a HotSpot error.

$ java -version
java version "1.3.0"
Java(TM) 2 Runtime Environment, Standard Edition (build mbron-000522-13:23)
Java HotSpot(TM) Client VM (build 1.3.0beta-b04, mixed mode)

$ java -jar Java2Demo.jar
# # An unexpected exception has been detected in native code outside the VM.# Program counter=0x40091598
#
# Problematic Thread: prio=1 tid=0x812ea40 nid=0x1c08 runnable
#
# # An unexpected exception has been detected in native code outside the VM.# Program counter=0x4074098a
#
# Problematic Thread: prio=1 tid=0x91e1c70 nid=0x18c17 runnable