Here is also the fedict.log crash detail:
2012-01-25 15:02:36,412 WARNÂ [AuthenticationServiceBean] eID Trust Service error: HTTP transport error: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target: com.sun.xml.ws.client.ClientTransportException: HTTP transport error: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
   at com.sun.xml.ws.transport.http.client.HttpClientTransport.getOutput(HttpClientTransport.java:135)
   at com.sun.xml.ws.transport.http.client.HttpTransportPipe.process(HttpTransportPipe.java:163)
   at com.sun.xml.ws.transport.http.client.HttpTransportPipe.processRequest(HttpTransportPipe.java:95)
   at com.sun.xml.ws.transport.DeferredTransportPipe.processRequest(DeferredTransportPipe.java:133)
   at com.sun.xml.ws.api.pipe.Fiber.__doRun(Fiber.java:629)
   at com.sun.xml.ws.api.pipe.Fiber._doRun(Fiber.java:588)
   at com.sun.xml.ws.api.pipe.Fiber.doRun(Fiber.java:573)
   at com.sun.xml.ws.api.pipe.Fiber.runSync(Fiber.java:470)
   at com.sun.xml.ws.client.Stub.process(Stub.java:319)
   at com.sun.xml.ws.client.sei.SEIStub.doProcess(SEIStub.java:157)
   at com.sun.xml.ws.client.sei.SyncMethodHandler.invoke(SyncMethodHandler.java:109)
   at com.sun.xml.ws.client.sei.SyncMethodHandler.invoke(SyncMethodHandler.java:89)
   at com.sun.xml.ws.client.sei.SEIStub.invoke(SEIStub.java:140)
   at $Proxy434.validate(Unknown Source)
   at be.fedict.trust.client.XKMS2Client.validate(XKMS2Client.java:562)
   at be.fedict.trust.client.XKMS2Client.validate(XKMS2Client.java:349)
   at be.fedict.trust.client.XKMS2Client.validate(XKMS2Client.java:331)
   at be.fedict.eid.idp.model.applet.AuthenticationServiceBean.validateCertificateChain(AuthenticationServiceBean.java:104)
   at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
   at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
   at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
   at java.lang.reflect.Method.invoke(Method.java:601)
   at org.jboss.aop.joinpoint.MethodInvocation.invokeTarget(MethodInvocation.java:122)
   at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:111)
   at org.jboss.ejb3.interceptors.container.ContainerMethodInvocationWrapper.invokeNext(ContainerMethodInvocationWrapper.java:72)
   at org.jboss.ejb3.interceptors.aop.InterceptorSequencer.invoke(InterceptorSequencer.java:76)
   at org.jboss.ejb3.interceptors.aop.InterceptorSequencer.aroundInvoke(InterceptorSequencer.java:62)
   at sun.reflect.GeneratedMethodAccessor534.invoke(Unknown Source)
   at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
   at java.lang.reflect.Method.invoke(Method.java:601)
   at org.jboss.aop.advice.PerJoinpointAdvice.invoke(PerJoinpointAdvice.java:174)
   at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
   at org.jboss.ejb3.interceptors.aop.InvocationContextInterceptor.fillMethod(InvocationContextInterceptor.java:74)
   at org.jboss.aop.advice.org.jboss.ejb3.interceptors.aop.InvocationContextInterceptor_z_fillMethod_22033424.invoke(InvocationContextInterceptor_z_fillMethod_22033424.java)
   at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
   at org.jboss.ejb3.interceptors.aop.InvocationContextInterceptor.setup(InvocationContextInterceptor.java:90)
   at org.jboss.aop.advice.org.jboss.ejb3.interceptors.aop.InvocationContextInterceptor_z_setup_22033424.invoke(InvocationContextInterceptor_z_setup_22033424.java)
   at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
   at org.jboss.ejb3.async.impl.interceptor.AsynchronousServerInterceptor.invoke(AsynchronousServerInterceptor.java:128)
   at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
   at org.jboss.ejb3.connectionmanager.CachedConnectionInterceptor.invoke(CachedConnectionInterceptor.java:62)
   at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
   at org.jboss.ejb3.entity.TransactionScopedEntityManagerInterceptor.invoke(TransactionScopedEntityManagerInterceptor.java:56)
   at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
   at org.jboss.ejb3.AllowedOperationsInterceptor.invoke(AllowedOperationsInterceptor.java:47)
   at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
   at org.jboss.ejb3.tx.NullInterceptor.invoke(NullInterceptor.java:42)
   at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
   at org.jboss.ejb3.stateless.StatelessInstanceInterceptor.invoke(StatelessInstanceInterceptor.java:68)
   at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
   at org.jboss.ejb3.core.context.SessionInvocationContextAdapter.proceed(SessionInvocationContextAdapter.java:95)
   at org.jboss.ejb3.tx2.impl.CMTTxInterceptor.invokeInOurTx(CMTTxInterceptor.java:247)
   at org.jboss.ejb3.tx2.impl.CMTTxInterceptor.required(CMTTxInterceptor.java:349)
   at org.jboss.ejb3.tx2.impl.CMTTxInterceptor.invoke(CMTTxInterceptor.java:209)
   at org.jboss.ejb3.tx2.aop.CMTTxInterceptorWrapper.invoke(CMTTxInterceptorWrapper.java:52)
   at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
   at org.jboss.aspects.tx.TxPropagationInterceptor.invoke(TxPropagationInterceptor.java:76)
   at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
   at org.jboss.ejb3.tx.NullInterceptor.invoke(NullInterceptor.java:42)
   at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
   at org.jboss.ejb3.security.Ejb3AuthenticationInterceptorv2.invoke(Ejb3AuthenticationInterceptorv2.java:182)
   at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
   at org.jboss.ejb3.ENCPropagationInterceptor.invoke(ENCPropagationInterceptor.java:41)
   at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
   at org.jboss.ejb3.BlockContainerShutdownInterceptor.invoke(BlockContainerShutdownInterceptor.java:67)
   at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
   at org.jboss.ejb3.core.context.CurrentInvocationContextInterceptor.invoke(CurrentInvocationContextInterceptor.java:47)
   at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
   at org.jboss.aspects.currentinvocation.CurrentInvocationInterceptor.invoke(CurrentInvocationInterceptor.java:67)
   at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
   at org.jboss.ejb3.interceptor.EJB3TCCLInterceptor.invoke(EJB3TCCLInterceptor.java:86)
   at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
   at org.jboss.ejb3.session.SessionSpecContainer.invoke(SessionSpecContainer.java:323)
   at org.jboss.ejb3.session.SessionSpecContainer.invoke(SessionSpecContainer.java:380)
   at sun.reflect.GeneratedMethodAccessor781.invoke(Unknown Source)
   at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
   at java.lang.reflect.Method.invoke(Method.java:601)
   at org.jboss.ejb3.proxy.impl.handler.session.SessionLocalProxyInvocationHandler$LocalContainerInvocation.invokeTarget(SessionLocalProxyInvocationHandler.java:184)
   at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:111)
   at org.jboss.ejb3.async.impl.interceptor.AsynchronousClientInterceptor.invoke(AsynchronousClientInterceptor.java:143)
   at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
   at org.jboss.ejb3.proxy.impl.handler.session.SessionLocalProxyInvocationHandler$LocalInvokableContextHandler.invoke(SessionLocalProxyInvocationHandler.java:159)
   at $Proxy335.invoke(Unknown Source)
   at org.jboss.ejb3.proxy.impl.handler.session.SessionProxyInvocationHandlerBase.invoke(SessionProxyInvocationHandlerBase.java:185)
   at $Proxy431.validateCertificateChain(Unknown Source)
   at be.fedict.eid.applet.service.impl.handler.AuthenticationDataMessageHandler.handleMessage(AuthenticationDataMessageHandler.java:286)
   at be.fedict.eid.applet.service.impl.handler.AuthenticationDataMessageHandler.handleMessage(AuthenticationDataMessageHandler.java:79)
   at be.fedict.eid.applet.service.AppletServiceServlet.doPost(AppletServiceServlet.java:310)
   at be.fedict.eid.idp.webapp.IdPAppletServiceServlet.doPost(IdPAppletServiceServlet.java:59)
   at javax.servlet.http.HttpServlet.service(HttpServlet.java:754)
   at javax.servlet.http.HttpServlet.service(HttpServlet.java:847)
   at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:324)
   at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:242)
   at be.fedict.eid.idp.webapp.SessionLoggingFilter.doFilter(SessionLoggingFilter.java:60)
   at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:274)
   at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:242)
   at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:83)
   at org.jboss.seam.web.RewriteFilter.doFilter(RewriteFilter.java:63)
   at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
   at org.jboss.seam.web.IdentityFilter.doFilter(IdentityFilter.java:40)
   at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
   at org.jboss.seam.web.MultipartFilter.doFilter(MultipartFilter.java:90)
   at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
   at org.jboss.seam.web.ExceptionFilter.doFilter(ExceptionFilter.java:64)
   at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
   at org.jboss.seam.web.RedirectFilter.doFilter(RedirectFilter.java:45)
   at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
   at org.ajax4jsf.webapp.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:206)
   at org.ajax4jsf.webapp.BaseFilter.handleRequest(BaseFilter.java:290)
   at org.ajax4jsf.webapp.BaseFilter.processUploadsAndHandleRequest(BaseFilter.java:388)
   at org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:515)
   at org.jboss.seam.web.Ajax4jsfFilter.doFilter(Ajax4jsfFilter.java:56)
   at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
   at org.jboss.seam.web.LoggingFilter.doFilter(LoggingFilter.java:60)
   at org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69)
   at org.jboss.seam.servlet.SeamFilter.doFilter(SeamFilter.java:158)
   at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:274)
   at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:242)
   at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:275)
   at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
   at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:181)
   at org.jboss.modcluster.catalina.CatalinaContext$RequestListenerValve.event(CatalinaContext.java:285)
   at org.jboss.modcluster.catalina.CatalinaContext$RequestListenerValve.invoke(CatalinaContext.java:261)
   at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:88)
   at org.jboss.web.tomcat.security.SecurityContextEstablishmentValve.invoke(SecurityContextEstablishmentValve.java:100)
   at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
   at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
   at org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:158)
   at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
   at org.jboss.web.tomcat.service.request.ActiveRequestResponseCacheValve.invoke(ActiveRequestResponseCacheValve.java:53)
   at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:362)
   at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:877)
   at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:654)
   at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:951)
   at java.lang.Thread.run(Thread.java:722)
Caused by: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
   at sun.security.ssl.Alerts.getSSLException(Alerts.java:192)
   at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1868)
   at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:276)
   at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:270)
   at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1337)
   at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:154)
   at sun.security.ssl.Handshaker.processLoop(Handshaker.java:868)
   at sun.security.ssl.Handshaker.process_record(Handshaker.java:804)
   at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:998)
   at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1294)
   at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1321)
   at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1305)
   at sun.net.www.protocol.https.HttpsClient.afterConnect(HttpsClient.java:523)
   at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:185)
   at sun.net.www.protocol.http.HttpURLConnection.getOutputStream(HttpURLConnection.java:1087)
   at sun.net.www.protocol.https.HttpsURLConnectionImpl.getOutputStream(HttpsURLConnectionImpl.java:250)
   at com.sun.xml.ws.transport.http.client.HttpClientTransport.getOutput(HttpClientTransport.java:123)
   ... 134 more
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
   at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:385)
   at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:292)
   at sun.security.validator.Validator.validate(Validator.java:260)
   at sun.security.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:326)
   at sun.security.ssl.X509TrustManagerImpl.checkTrusted(X509TrustManagerImpl.java:231)
   at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:126)
   at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1319)
   ... 146 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
   at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(SunCertPathBuilder.java:196)
   at java.security.cert.CertPathBuilder.build(CertPathBuilder.java:268)
   at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:380)
   ... 152 more