Coredump when using XalanTransformer.transform()

[mv...@amadeus.net]

Hello,

I am using Xalan ver. 1.2 and Xerces ver. 1.5. on HP-UX 11.00. I rebuilt 
the libraries with the following options:

runConfigure -p hp-11 -c cc -x aCC -d -r pthread
gmake

I am running a multithreaded application (currently only 2 threads). Each 
thread performs XSL transformation using the following code:

Each thread, after it has been created, calls the initialization:
XMLPlatformUtils::Initialize() ;
XalanTransformer::initialize() ;

before it stops, it does clean-up:
XalanTransformer::terminate() ;
XMLPlatformUtils::Terminate() ;

and in between repeatedly (some hundreds of times) performs transformation 
using XalanTransformer class and memory streams:

XalanTransformer  theTransformer ;

istrstream      theXMLStream( x.GetOutMsg(), x.GetOutMsgLength() ) ;
istrstream      theXSLStream( pMessage->GetXSL().IntBufNotNull(), 
pMessage->GetXSL().Length() ) ;
ostrstream  theOutStream ;

// ---- Set style sheet parameter "UID" equals to ulUID
theTransformer.setStylesheetParam( XalanDOMString(XSL_PARAM_UID), 
XalanDOMString(svUID) ) ;
// ---- Perform Xalan transformation
if( theTransformer.transform( &theXMLStream, &theXSLStream, &theOutStream 
) == 0 )
  {
  ...

If the traffic is high, the application coredumps in call to the 
transform() method. The stack is:
from transform() call to /opt/aCC/include/tree.cc (14 levels incl. 
endElement and erase).
If I am running one thread, everything is alright - no coredump.

The stack:
erase(iterator&,iterator)
erase(iterator&,iterator,iterator)
erase(ElemTemplateElement *&)
endElement
endElement
scanEndTag
scanContent
scanDocument(InputSource&,?)
parse(InputSource&,?)
parseXMLStream(InputSource&,DocumentHandler&,XalanDOMString&)
parseXMLStream(InputSource&,DocumentHandler&,XalanDOMString&)
processStylesheet(XSLTInputSource&,StylesheetConstructionContext&)
...
process(XSLTInputSource&,XSLTInputSource&,XSLTResultTarget&)

My question is: Did I do anything wrong? Any help appreciated.
Thanks in advance, Miro.