Crosstab problems

Hi
I am new to Jasper/IReports. I am using IReports1.2.3/Jasper1.2.3 and trying to create a crosstab report. I am getting the following errors.

net.sf.jasperreports.engine.JRException:ÂCrosstabÂdataÂhasÂalreadyÂbeenÂprocessed. ÂÂÂÂatÂnet.sf.jasperreports.crosstabs.fill.calculation.BucketingService.addData(BucketingService.java:280) ÂÂÂÂatÂnet.sf.jasperreports.engine.fill.JRFillCrosstab$JRFillCrosstabDataset.customIncrement(JRFillCrosstab.java:634) ÂÂÂÂatÂnet.sf.jasperreports.engine.fill.JRFillElementDataset.increment(JRFillElementDataset.java:134) ÂÂÂÂatÂnet.sf.jasperreports.engine.fill.JRCalculator.calculateVariables(JRCalculator.java:154) ÂÂÂÂatÂnet.sf.jasperreports.engine.fill.JRVerticalFiller.fillDetail(JRVerticalFiller.java:621) ÂÂÂÂatÂnet.sf.jasperreports.engine.fill.JRVerticalFiller.fillReportStart(JRVerticalFiller.java:228) ÂÂÂÂatÂnet.sf.jasperreports.engine.fill.JRVerticalFiller.fillReport(JRVerticalFiller.java:128) ÂÂÂÂatÂnet.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:750) ÂÂÂÂatÂnet.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:647) ÂÂÂÂatÂnet.sf.jasperreports.engine.fill.JRFiller.fillReport(JRFiller.java:63) ÂÂÂÂatÂnet.sf.jasperreports.engine.JasperFillManager.fillReport(JasperFillManager.java:402) ÂÂÂÂatÂnet.sf.jasperreports.engine.JasperFillManager.fillReport(JasperFillManager.java:234) ÂÂÂÂatÂit.businesslogic.ireport.IReportCompiler.run(IReportCompiler.java:701) ÂÂÂÂatÂjava.lang.Thread.run(UnknownÂSource) NESTEDÂBYÂ: net.sf.jasperreports.engine.JRException:ÂCrosstabÂdataÂhasÂalreadyÂbeenÂprocessed. ÂÂÂÂatÂnet.sf.jasperreports.crosstabs.fill.calculation.BucketingService.addData(BucketingService.java:280) ÂÂÂÂatÂnet.sf.jasperreports.engine.fill.JRFillCrosstab$JRFillCrosstabDataset.customIncrement(JRFillCrosstab.java:634) ÂÂÂÂatÂnet.sf.jasperreports.engine.fill.JRFillElementDataset.increment(JRFillElementDataset.java:134) ÂÂÂÂatÂnet.sf.jasperreports.engine.fill.JRCalculator.calculateVariables(JRCalculator.java:154) ÂÂÂÂatÂnet.sf.jasperreports.engine.fill.JRVerticalFiller.fillDetail(JRVerticalFiller.java:621) ÂÂÂÂatÂnet.sf.jasperreports.engine.fill.JRVerticalFiller.fillReportStart(JRVerticalFiller.java:228) ÂÂÂÂatÂnet.sf.jasperreports.engine.fill.JRVerticalFiller.fillReport(JRVerticalFiller.java:128) ÂÂÂÂatÂnet.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:750) ÂÂÂÂatÂnet.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:647) ÂÂÂÂatÂnet.sf.jasperreports.engine.fill.JRFiller.fillReport(JRFiller.java:63) ÂÂÂÂatÂnet.sf.jasperreports.engine.JasperFillManager.fillReport(JasperFillManager.java:402) ÂÂÂÂatÂnet.sf.jasperreports.engine.JasperFillManager.fillReport(JasperFillManager.java:234) ÂÂÂÂatÂit.businesslogic.ireport.IReportCompiler.run(IReportCompiler.java:701) ÂÂÂÂatÂjava.lang.Thread.run(UnknownÂSource) NESTEDÂBYÂ: net.sf.jasperreports.engine.JRRuntimeException:ÂErrorÂincrementingÂcrosstabÂdataset ÂÂÂÂatÂnet.sf.jasperreports.engine.fill.JRFillCrosstab$JRFillCrosstabDataset.customIncrement(JRFillCrosstab.java:638) ÂÂÂÂatÂnet.sf.jasperreports.engine.fill.JRFillElementDataset.increment(JRFillElementDataset.java:134) ÂÂÂÂatÂnet.sf.jasperreports.engine.fill.JRCalculator.calculateVariables(JRCalculator.java:154) ÂÂÂÂatÂnet.sf.jasperreports.engine.fill.JRVerticalFiller.fillDetail(JRVerticalFiller.java:621) ÂÂÂÂatÂnet.sf.jasperreports.engine.fill.JRVerticalFiller.fillReportStart(JRVerticalFiller.java:228) ÂÂÂÂatÂnet.sf.jasperreports.engine.fill.JRVerticalFiller.fillReport(JRVerticalFiller.java:128) ÂÂÂÂatÂnet.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:750) ÂÂÂÂatÂnet.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:647) ÂÂÂÂatÂnet.sf.jasperreports.engine.fill.JRFiller.fillReport(JRFiller.java:63) ÂÂÂÂatÂnet.sf.jasperreports.engine.JasperFillManager.fillReport(JasperFillManager.java:402) ÂÂÂÂatÂnet.sf.jasperreports.engine.JasperFillManager.fillReport(JasperFillManager.java:234) ÂÂÂÂatÂit.businesslogic.ireport.IReportCompiler.run(IReportCompiler.java:701) ÂÂÂÂatÂjava.lang.Thread.run(UnknownÂSource) CausedÂby:Ânet.sf.jasperreports.engine.JRException:ÂCrosstabÂdataÂhasÂalreadyÂbeenÂprocessed. ÂÂÂÂatÂnet.sf.jasperreports.crosstabs.fill.calculation.BucketingService.addData(BucketingService.java:280) ÂÂÂÂatÂnet.sf.jasperreports.engine.fill.JRFillCrosstab$JRFillCrosstabDataset.customIncrement(JRFillCrosstab.java:634) ÂÂÂÂ...Â12Âmore
PrintÂnotÂfilled.ÂTryÂtoÂuseÂanÂEmptyDataSource...!

Please help me with the solution. It is urgent.

Thanx in advance.