Error occurred while running on JDK1.3 but still works good in JDK1.4( not version mismatch nor compliation errors)

Question

Hi When I am running a Java class in Eclipse using JAVA/JDK 1.4 its working fine but the same is throwing the following error in JDK 1.3. This is not around version mismatch but something else if you would see the following exception thrown.

    [05/03/10 14:51:46:787 IST] 31cf31cf SystemOut O 2010.03.05 14:51:46.787 com.ibm.commerce.command.ECCommandTarget executeCommand

    CMN0420E: The following CommandException occurred during processing: "java.lang.VerifyError: java.lang.SecurityException:
 Package name not allowed - 'java.net'".java.lang.VerifyError: java.lang.SecurityException: Package name not allowed - 'java.net'

at java.lang.Throwable.<init>(Throwable.java)

at java.lang.Throwable.<init>(Throwable.java)

at java.lang.Class.verify(Class.java)

at java.lang.Class.initialize(Class.java)

at com.octo.captcha.component.sound.wordtosound.FreeTTSWordToSound.<init>(FreeTTSWordToSound.java:181)

at com.o2.ecrm.captcha.util.O2CaptchaService.<clinit>(O2CaptchaService.java:76)

at java.lang.Class.initializeImpl(Native Method)

at java.lang.Class.initialize(Class.java)

at com.o2.ecrm.shop.commands.O2RetrievePinPukCodeStep1CmdImpl.performExecute(O2RetrievePinPukCodeStep1CmdImpl.java:126)

at com.ibm.commerce.command.ECCommandTarget.executeCommand(ECCommandTarget.java:133)

at com.ibm.websphere.command.TargetableCommandImpl.execute(TargetableCommandImpl.java:135)

at com.ibm.websphere.command.CacheableCommandImpl.execute(CacheableCommandImpl.java:134)

at com.ibm.commerce.command.AbstractECTargetableCommand.execute(AbstractECTargetableCommand.java:180)

at com.ibm.commerce.webcontroller.ControllerCmdExecUnit.execute(ControllerCmdExecUnit.java:220)

at com.ibm.commerce.webcontroller.WebController.executeTransaction(WebController.java:239)

at com.ibm.commerce.webcontroller.WebController.processRequest(WebController.java:947)

at com.ibm.commerce.adapter.AbstractHttpAdapter.processRequest(AbstractHttpAdapter.java:350)

at com.ibm.commerce.server.RequestServlet$2.run(RequestServlet.java:1708)

at com.ibm.commerce.server.RequestServlet.service(RequestServlet.java:1810)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)

Could anyone explain me this probelm