ClassCastException: MemberException

Hi people.

I've been using and testing jasperintelligence for 2 months and after many hard tests on the software, I got the Exception below. I tried to do a lot of customizations in schema and database tables, but I couldn't find a solution. This happens when I click on the Time link available on Rows area of the Cube navigator....but sometimes it works fine and sometimes the Exception is throwed.
Can anyone help me how to resolve this problem ?

JPivot had an error ... java.lang.ClassCastException: mondrian.mdx.MemberExpr java.lang.ClassCastException: mondrian.mdx.MemberExpr at com.tonbeller.jpivot.mondrian.MondrianUtil$1.handleTreeNode(MondrianUtil.java:308) at com.tonbeller.jpivot.util.TreeNode.walkChildren(TreeNode.java:138) at com.tonbeller.jpivot.mondrian.MondrianUtil.collectMembers(MondrianUtil.java:288) at com.tonbeller.jpivot.mondrian.MondrianPlaceMembers.findVisibleMembers(MondrianPlaceMembers.java:76) at com.tonbeller.jpivot.navigator.hierarchy.HierarchyItem.initializeAxisSelection(HierarchyItem.java:103) at com.tonbeller.jpivot.navigator.hierarchy.HierarchyItem.getAxisSelection(HierarchyItem.java:159) at com.tonbeller.jpivot.navigator.hierarchy.AxisCategory.itemClicked(AxisCategory.java:66) at com.tonbeller.jpivot.navigator.hierarchy.HierarchyItem.request(HierarchyItem.java:150) at com.tonbeller.wcf.controller.DispatcherSupport.request(DispatcherSupport.java:167) at com.tonbeller.wcf.controller.DispatcherSupport.request(DispatcherSupport.java:167) at com.tonbeller.wcf.component.ComponentSupport.request(ComponentSupport.java:104) at com.tonbeller.wcf.controller.WcfController.request(WcfController.java:71) at com.tonbeller.wcf.controller.RequestFilter$MyHandler.normalRequest(RequestFilter.java:119) at com.tonbeller.wcf.controller.RequestSynchronizer.handleRequest(RequestSynchronizer.java:127) at com.tonbeller.wcf.controller.RequestFilter.doFilter(RequestFilter.java:263) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173) at com.jaspersoft.jasperserver.war.common.UploadMultipartFilter.doFilter(UploadMultipartFilter.java:83) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173) at org.acegisecurity.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:264) at org.acegisecurity.intercept.web.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:107) at org.acegisecurity.intercept.web.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:72) at org.acegisecurity.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:274) at org.acegisecurity.ui.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:110) at org.acegisecurity.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:274) at org.acegisecurity.providers.anonymous.AnonymousProcessingFilter.doFilter(AnonymousProcessingFilter.java:125) at org.acegisecurity.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:274) at com.jaspersoft.jasperserver.api.metadata.user.service.impl.MetadataAuthenticationProcessingFilter.doFilter(MetadataAuthenticationProcessingFilter.java:136) at org.acegisecurity.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:274) at org.acegisecurity.ui.basicauth.BasicProcessingFilter.doFilter(BasicProcessingFilter.java:181) at org.acegisecurity.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:274) at org.acegisecurity.ui.AbstractProcessingFilter.doFilter(AbstractProcessingFilter.java:216) at org.acegisecurity.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:274) at org.acegisecurity.context.HttpSessionContextIntegrationFilter.doFilter(HttpSessionContextIntegrationFilter.java:195) at org.acegisecurity.util.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:274) at org.acegisecurity.util.FilterChainProxy.doFilter(FilterChainProxy.java:148) at org.acegisecurity.util.FilterToBeanProxy.doFilter(FilterToBeanProxy.java:90) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213) at org.apache.catalina.core.StandardContextValve.invoke(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.invoke(StandardEngineValve.java:107) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148) at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:833) at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:639) at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1285) at java.lang.Thread.run(Unknown Source)

Thx
RHancke