JVM interference with Xerces :System hangs

I parse(using DOMParser) a huge XML (about 20 KB) in to DOM and serialize it
to print the XML out of it , repeatedly.
My system does the job as expected over a number of times(up to 6 times run
continuously) and then
hangs ending up with a Null pointer Exception as described below.

java.lang.NullPointerException
	at
org.apache.xerces.dom.DeferredDocumentImpl.synchronizeChildren(DeferredDocum
entImpl.java:1218)
	at org.apache.xerces.dom.NodeImpl.getChildNodes(NodeImpl.java:520)

To my knowledge this is because JVM HotSpot interferes with Xerces when we
try to parse huge xml files repeatedly.

I am using :
Xerces1.4.3 on Java 2 platform.

Have you guys come across this situation.

I would really appreciate any ideas about the solution to this problem.
I apologize if this mail went in to wrong mailing list.

Thank you,
Andrew