java.lang.IllegalAccessError: org/apache/xml/serializer/ExtendedContentHandler

I am using Jasper Report to run the reports using jdk1.4 and tomcat 4.1. I am getting following error. I have xalan-2.7.1.jar, xercesImpl.jar and serializer-2.7.1.jar

java.lang.IllegalAccessError: org/apache/xml/serializer/ExtendedContentHandler at org.apache.xalan.templates.ElemLiteralResult.execute(ElemLiteralResult.java:1321) at org.apache.xalan.transformer.TransformerImpl.executeChildTemplates(TransformerImpl.java:2400) at org.apache.xalan.transformer.TransformerImpl.applyTemplateToNode(TransformerImpl.java:2270) at org.apache.xalan.transformer.TransformerImpl.transformNode(TransformerImpl.java:1356) at org.apache.xalan.transformer.TransformerImpl.run(TransformerImpl.java:3447) at org.apache.xalan.transformer.TransformerHandlerImpl.endDocument(TransformerHandlerImpl.java:408) at org.apache.xerces.parsers.AbstractSAXParser.endDocument(Unknown Source) at org.apache.xerces.impl.XMLDocumentScannerImpl.endEntity(Unknown Source) at org.apache.xerces.impl.XMLEntityManager.endEntity(Unknown Source) at org.apache.xerces.impl.XMLEntityScanner.load(Unknown Source) at org.apache.xerces.impl.XMLEntityScanner.skipSpaces(Unknown Source) at org.apache.xerces.impl.XMLDocumentScannerImpl$TrailingMiscDispatcher.dispatch(Unknown Source) at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source) at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source) at org.apache.xerces.parsers.DTDConfiguration.parse(Unknown Source) at org.apache.xerces.parsers.XMLParser.parse(Unknown Source) at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source) at org.apache.xalan.transformer.TrAXFilter.parse(TrAXFilter.java:164) at org.apache.fop.apps.Driver.render(Driver.java:481)

I am using following code for rendering report

ByteArrayOutputStream out = new ByteArrayOutputStream(); Driver driver = new Driver(); driver.setRenderer(Driver.RENDER_PDF); driver.setOutputStream(out); driver.render(input.getParser(), input.getInputSource());

Thanks in advance.