Help with XSLT error

[Steve Pavett <st...@evolution.net>]

I'm currently getting an error with a system I'm developing against Xalan J2
v2.0.0 and 2.0.1. I am finding it impossible to track down why this is
happening and wondered if it was obvious to someone on this list. On
performing a transformation I'm getting this exception (it seems to be
intermittent - every second and third time I call transform):

javax.xml.transform.TransformerException
        at
org.apache.xalan.transformer.TransformerImpl.transformNode(TransformerImpl.j
ava:1212)
        at
org.apache.xalan.transformer.TransformerImpl.run(TransformerImpl.java:2894)
        at java.lang.Thread.run(Thread.java:484)
---------
java.lang.ArrayIndexOutOfBoundsException at
org.apache.xml.utils.NodeVector.popPair(NodeVector.java:307)
        at
org.apache.xalan.transformer.TransformerImpl.popCurrentMatched(TransformerIm
pl.java:2372)
        at
org.apache.xalan.transformer.TransformerImpl.applyTemplateToNode(Transformer
Impl.java:2038)
        at
org.apache.xalan.transformer.TransformerImpl.transformNode(TransformerImpl.j
ava:1189)
        at
org.apache.xalan.transformer.TransformerImpl.run(TransformerImpl.java:2894)
        at java.lang.Thread.run(Thread.java:484)

Any ideas on what causes this would be welcomed.

Steve