[#5826] - Invalid method Code length in iReport 4.5.1

Hi
Please help...

My environment :-
1)Windows 7 Prof 32bits
2)Product Version: Jaspersoft iReport Designer 4.5.0
Java: 1.6.0_31; Java HotSpot(TM) Client VM 20.6-b01
System: Windows 7 version 6.1 running on x86; Cp1252; en_US (ireport)
Userdir: C:\Users\Asus\.ireport\4.5.0
3) MySQL version 5

I got the Invalid method Code length 66386 and please refer to below for more information. It is suspect from variable expression. Please advice. Thanks
Regards
Gilbert

Compiling to file... C:\Program Files\Apache Software Foundation\Apache2.2\htdocs\Netwin\application\reports\debtorstmt.jasper
Compilation running time: 1,345!
 Filling report...
 Locale: English (United States)
 Time zone: Default
Error filling print... java.lang.ClassFormatError: Invalid method Code length 66386 in class file debtorstmt_1341844352250_822872 null
java.lang.ClassFormatError: Invalid method Code length 66386 in class file debtorstmt_1341844352250_822872      at java.lang.ClassLoader.defineClass1(Native Method)      at java.lang.ClassLoader.defineClassCond(Unknown Source)      at java.lang.ClassLoader.defineClass(Unknown Source)      at net.sf.jasperreports.engine.util.JRClassLoader.loadClass(JRClassLoader.java:338)      at net.sf.jasperreports.engine.util.JRClassLoader.loadClassFromBytes(JRClassLoader.java:239)      at net.sf.jasperreports.engine.design.JRAbstractJavaCompiler.loadEvaluator(JRAbstractJavaCompiler.java:88)      at net.sf.jasperreports.engine.design.JRAbstractCompiler.loadEvaluator(JRAbstractCompiler.java:320)      at net.sf.jasperreports.engine.JasperCompileManager.loadEvaluator(JasperCompileManager.java:237)      at net.sf.jasperreports.engine.fill.JRFillDataset.createCalculator(JRFillDataset.java:427)      at net.sf.jasperreports.engine.fill.JRBaseFiller.<init>(JRBaseFiller.java:363)      at net.sf.jasperreports.engine.fill.JRVerticalFiller.<init>(JRVerticalFiller.java:77)      at net.sf.jasperreports.engine.fill.JRVerticalFiller.<init>(JRVerticalFiller.java:87)      at net.sf.jasperreports.engine.fill.JRVerticalFiller.<init>(JRVerticalFiller.java:57)      at net.sf.jasperreports.engine.fill.JRFiller.createFiller(JRFiller.java:142)      at net.sf.jasperreports.engine.fill.JRFiller.fillReport(JRFiller.java:52)      at net.sf.jasperreports.engine.JasperFillManager.fillReport(JasperFillManager.java:417)      at net.sf.jasperreports.engine.JasperFillManager.fillReport(JasperFillManager.java:247)      at com.jaspersoft.ireport.designer.compiler.IReportCompiler.run(IReportCompiler.java:879)      at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:572)      at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:997) 
Print not filled. Try to use an EmptyDataSource...