I am using jcaptcha for image verification code in my application.It is j2ee application and tomcat server is used.Sometimes I am getting an exception saying "com.octo.captcha.service.CaptchaServiceExcept ion: Invalid ID, could not validate!
    at com.octo.captcha.service.AbstractCaptchaService.va lidateResponseForID(AbstractCaptchaService.java:13 8)
    at com.octo.captcha.service.AbstractManageableCaptcha Service.validateResponseForID(AbstractManageableCa ptchaService.java:364)
    at no.finntech.kernel.util.ImageCaptchaUtil.validateV erificationCode(ImageCaptchaUtil.java:28)
    at no.finntech.base.modules.shared.actions.RequestPas swordChangeAction.extendService(RequestPasswordCha ngeAction.java:84)
    at no.finntech.kernel.navigation.DispatcherTemplate.c allAction(DispatcherTemplate.java:1408)
    at no.finntech.kernel.navigation.MainDispatcher.doSer vice(MainDispatcher.java:224)
    at no.finntech.kernel.navigation.DispatcherTemplate.s ervice(DispatcherTemplate.java:1662)
    at javax.servlet.http.HttpServlet.service(HttpServlet .java:802)
    at org.apache.catalina.core.ApplicationFilterChain.in ternalDoFilter(ApplicationFilterChain.java:252)
    at org.apache.catalina.core.ApplicationFilterChain.do Filter(ApplicationFilterChain.java:175)
    at no.finntech.kernel.framework.upload.MultipartFilte r.doFilter(MultipartFilter.java:59)
    at org.apache.catalina.core.ApplicationFilterChain.in ternalDoFilter(ApplicationFilterChain.java:202)
    at org.apache.catalina.core.ApplicationFilterChain.do Filter(ApplicationFilterChain.java:175)
    at org.apache.catalina.core.StandardWrapperValve.invo ke(StandardWrapperValve.java:204)
    at org.apache.catalina.core.StandardContextValve.invo ke(StandardContextValve.java:178)
    at org.apache.catalina.core.StandardHostValve.invoke( StandardHostValve.java:126)
    at org.apache.catalina.valves.ErrorReportValve.invoke (ErrorReportValve.java:105)
    at org.apache.catalina.core.StandardEngineValve.invok e(StandardEngineValve.java:107)
    at org.apache.catalina.connector.CoyoteAdapter.servic e(CoyoteAdapter.java:148)
    at org.apache.coyote.http11.Http11Processor.process(H ttp11Processor.java:869)
    at org.apache.coyote.http11.Http11BaseProtocol$Http11 ConnectionHandler.processConnection(Http11BaseProt ocol.java:667)
    at org.apache.tomcat.util.net.PoolTcpEndpoint.process Socket(PoolTcpEndpoint.java:527)
    at org.apache.tomcat.util.net.LeaderFollowerWorkerThr ead.runIt(LeaderFollowerWorkerThread.java:80)
    at org.apache.tomcat.util.threads.ThreadPool$ControlR unnable.run(ThreadPool.java:684)
    at java.lang.Thread.run()V(Unknown Source)"

How to solve this issue?If any one knows,please help me