Ireport com sub-relatório

Galera tenho um relatório principal dentro dele eu chamo um sub-relatório o código que chama o rel principal segue


import java.util.HashMap;
import java.util.Map;

import javax.swing.JOptionPane;

import net.sf.jasperreports.engine.JRException;
import net.sf.jasperreports.engine.JRResultSetDataSource;
import net.sf.jasperreports.engine.JasperFillManager;
import net.sf.jasperreports.engine.JasperPrint;
import net.sf.jasperreports.view.JasperViewer;

public class ImprimiChamados {
		 
	private String dir = "C:\java\sysChamados\";
	private String relatorio,setTitle;
		
	public ImprimiChamados(){
			
		relatorio	= "chamados.jasper";
		setTitle	= "Relatório de Chamados";
				
		Map parameters = new HashMap();
				
		try {
			ChamadosSql sql = new ChamadosSql();
			
			JRResultSetDataSource jrRS1 = new JRResultSetDataSource(sql.ImprimirChamados());
			JasperPrint print;
			print = JasperFillManager.fillReport(dir+relatorio,parameters,jrRS1);
			JasperViewer jrviewer = new JasperViewer(print,false);
			jrviewer.setTitle(setTitle);
			jrviewer.setVisible(true);
			
		} catch (JRException e) {
			JOptionPane.showMessageDialog( null, e.getMessage(), "Aviso",
		    JOptionPane.WARNING_MESSAGE );
		}  
		
		
	}
}

ele está dando erro qd executo o sistema, gera a seguinte erro

java.lang.NoSuchMethodError: org.apache.log4j.spi.LoggingEvent.getThrowableStrRep()[Ljava/lang/String;
	at org.apache.log4j.WriterAppender.subAppend(WriterAppender.java:295)
	at org.apache.log4j.WriterAppender.append(WriterAppender.java:150)
	at org.apache.log4j.AppenderSkeleton.doAppend(AppenderSkeleton.java:221)
	at org.apache.log4j.helpers.AppenderAttachableImpl.appendLoopOnAppenders(AppenderAttachableImpl.java:56)
	at org.apache.log4j.Category.callAppenders(Category.java:258)
	at org.apache.log4j.Category.forcedLog(Category.java:454)
	at org.apache.log4j.Category.log(Category.java:885)
	at org.apache.commons.logging.impl.Log4JCategoryLog.warn(Log4JCategoryLog.java:196)
	at net.sf.jasperreports.engine.query.JRJdbcQueryExecuter.<init>(JRJdbcQueryExecuter.java:83)
	at net.sf.jasperreports.engine.query.JRJdbcQueryExecuterFactory.createQueryExecuter(JRJdbcQueryExecuterFactory.java:84)
	at net.sf.jasperreports.engine.fill.JRFillDataset.createQueryDatasource(JRFillDataset.java:659)
	at net.sf.jasperreports.engine.fill.JRFillDataset.setDatasource(JRFillDataset.java:606)
	at net.sf.jasperreports.engine.fill.JRFillDataset.setParameterValues(JRFillDataset.java:595)
	at net.sf.jasperreports.engine.fill.JRBaseFiller.setParameters(JRBaseFiller.java:879)
	at net.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:708)
	at net.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:666)
	at net.sf.jasperreports.engine.fill.JRFillSubreport.fillSubreport(JRFillSubreport.java:494)
	at net.sf.jasperreports.engine.fill.JRSubreportRunnable.run(JRSubreportRunnable.java:63)
	at net.sf.jasperreports.engine.fill.JRThreadSubreportRunner.run(JRThreadSubreportRunner.java:137)
	at java.lang.Thread.run(Unknown Source)

NESTED BY :
net.sf.jasperreports.engine.JRRuntimeException: org.apache.log4j.spi.LoggingEvent.getThrowableStrRep()[Ljava/lang/String;
	at net.sf.jasperreports.engine.fill.JRFillSubreport.prepare(JRFillSubreport.java:583)
	at net.sf.jasperreports.engine.fill.JRFillElementContainer.prepareElements(JRFillElementContainer.java:345)
	at net.sf.jasperreports.engine.fill.JRFillBand.fill(JRFillBand.java:311)
	at net.sf.jasperreports.engine.fill.JRFillBand.fill(JRFillBand.java:275)
	at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillColumnBand(JRVerticalFiller.java:1291)
	at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillDetail(JRVerticalFiller.java:631)
	at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillReportStart(JRVerticalFiller.java:228)
	at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillReport(JRVerticalFiller.java:128)
	at net.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:758)
	at net.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:685)
	at net.sf.jasperreports.engine.fill.JRFiller.fillReport(JRFiller.java:89)
	at net.sf.jasperreports.engine.JasperFillManager.fillReport(JasperFillManager.java:601)
	at net.sf.jasperreports.engine.JasperFillManager.fillReport(JasperFillManager.java:517)
	at ImprimiChamados.<init>(ImprimiChamados.java:48)
	at Sistema$4.actionPerformed(Sistema.java:133)
	at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
	at javax.swing.AbstractButton$ForwardActionEvents.actionPerformed(Unknown Source)
	at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
	at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
	at javax.swing.AbstractButton.doClick(Unknown Source)
	at javax.swing.plaf.basic.BasicMenuItemUI.doClick(Unknown Source)
	at javax.swing.plaf.basic.BasicMenuItemUI$MouseInputHandler.mouseReleased(Unknown Source)
	at java.awt.Component.processMouseEvent(Unknown Source)
	at java.awt.Component.processEvent(Unknown Source)
	at java.awt.Container.processEvent(Unknown Source)
	at java.awt.Component.dispatchEventImpl(Unknown Source)
	at java.awt.Container.dispatchEventImpl(Unknown Source)
	at java.awt.Component.dispatchEvent(Unknown Source)
	at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
	at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
	at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
	at java.awt.Container.dispatchEventImpl(Unknown Source)
	at java.awt.Window.dispatchEventImpl(Unknown Source)
	at java.awt.Component.dispatchEvent(Unknown Source)
	at java.awt.EventQueue.dispatchEvent(Unknown Source)
	at java.awt.EventDispatchThread.pumpOneEventForHierarchy(Unknown Source)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
	at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
	at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
	at java.awt.EventDispatchThread.run(Unknown Source)
Caused by: java.lang.NoSuchMethodError: org.apache.log4j.spi.LoggingEvent.getThrowableStrRep()[Ljava/lang/String;
	at org.apache.log4j.WriterAppender.subAppend(WriterAppender.java:295)
	at org.apache.log4j.WriterAppender.append(WriterAppender.java:150)
	at org.apache.log4j.AppenderSkeleton.doAppend(AppenderSkeleton.java:221)
	at org.apache.log4j.helpers.AppenderAttachableImpl.appendLoopOnAppenders(AppenderAttachableImpl.java:56)
	at org.apache.log4j.Category.callAppenders(Category.java:258)
	at org.apache.log4j.Category.forcedLog(Category.java:454)
	at org.apache.log4j.Category.log(Category.java:885)
	at org.apache.commons.logging.impl.Log4JCategoryLog.warn(Log4JCategoryLog.java:196)
	at net.sf.jasperreports.engine.query.JRJdbcQueryExecuter.<init>(JRJdbcQueryExecuter.java:83)
	at net.sf.jasperreports.engine.query.JRJdbcQueryExecuterFactory.createQueryExecuter(JRJdbcQueryExecuterFactory.java:84)
	at net.sf.jasperreports.engine.fill.JRFillDataset.createQueryDatasource(JRFillDataset.java:659)
	at net.sf.jasperreports.engine.fill.JRFillDataset.setDatasource(JRFillDataset.java:606)
	at net.sf.jasperreports.engine.fill.JRFillDataset.setParameterValues(JRFillDataset.java:595)
	at net.sf.jasperreports.engine.fill.JRBaseFiller.setParameters(JRBaseFiller.java:879)
	at net.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:708)
	at net.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:666)
	at net.sf.jasperreports.engine.fill.JRFillSubreport.fillSubreport(JRFillSubreport.java:494)
	at net.sf.jasperreports.engine.fill.JRSubreportRunnable.run(JRSubreportRunnable.java:63)
	at net.sf.jasperreports.engine.fill.JRThreadSubreportRunner.run(JRThreadSubreportRunner.java:137)
	at java.lang.Thread.run(Unknown Source)

Se eu tirar o sub-relatório do rel principal dai ele funciona!