LoginFilter barfs on Sun ONE 7

The LoginFilter throws ClassCastException on Sun ONE 7. Any ideas? This should be servlet api 2.3 so not sure where it comes from. It works fine on Orion.

I already tried changing the order of non seraph filters (put sitemesh to the end) but it didn't help.

SEVERE: ApplicationDispatcher[/izhp] Servlet.service() for servlet jsp threw exception
java.lang.ClassCastException
at com.sun.web.server.J2EEInstanceListener.handleBeforeEvent(J2EEInstanceListener.java:142)
at com.sun.web.server.J2EEInstanceListener.instanceEvent(J2EEInstanceListener.java:80)
at org.apache.catalina.util.InstanceSupport.fireInstanceEvent(InstanceSupport.java:342)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:700)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:444)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:363)
at webwork.dispatcher.ServletDispatcher.service(ServletDispatcher.java:213)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:247)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at com.opensymphony.module.sitemesh.filter.PageFilter.parsePage(Unknown Source)
at com.opensymphony.module.sitemesh.filter.PageFilter.doFilter(Unknown Source)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:213)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at com.atlassian.seraph.filter.SecurityFilter.doFilter(Unknown Source)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:213)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at com.atlassian.seraph.filter.LoginFilter.doFilter(Unknown Source)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:213)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:265)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:505)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:212)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:505)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:203)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:505)
at com.iplanet.ias.web.connector.nsapi.NSAPIProcessor.process(NSAPIProcessor.java:157)
at com.iplanet.ias.web.WebContainer.service(WebContainer.java:598)

SEVERE: WEB5003: Exception in handleAfterEvent.
com.sun.enterprise.InvocationException
at com.sun.enterprise.util.InvocationManagerImpl.postInvoke(InvocationManagerImpl.java:159)
at com.sun.web.server.J2EEInstanceListener.handleAfterEvent(J2EEInstanceListener.java:201)
at com.sun.web.server.J2EEInstanceListener.instanceEvent(J2EEInstanceListener.java:86)
at org.apache.catalina.util.InstanceSupport.fireInstanceEvent(InstanceSupport.java:262)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:228)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:265)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:505)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:212)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:505)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:203)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:505)
at com.iplanet.ias.web.connector.nsapi.NSAPIProcessor.process(NSAPIProcessor.java:157)
at com.iplanet.ias.web.WebContainer.service(WebContainer.java:598)

SEVERE: StandardWrapperValve[action]: Servlet.service() for servlet action threw exception
java.lang.ClassCastException
at com.sun.web.server.J2EEInstanceListener.handleBeforeEvent(J2EEInstanceListener.java:142)
at com.sun.web.server.J2EEInstanceListener.instanceEvent(J2EEInstanceListener.java:80)
at org.apache.catalina.util.InstanceSupport.fireInstanceEvent(InstanceSupport.java:342)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:700)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:444)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:363)
at webwork.dispatcher.ServletDispatcher.service(ServletDispatcher.java:213)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:247)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at com.opensymphony.module.sitemesh.filter.PageFilter.parsePage(Unknown Source)
at com.opensymphony.module.sitemesh.filter.PageFilter.doFilter(Unknown Source)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:213)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at com.atlassian.seraph.filter.SecurityFilter.doFilter(Unknown Source)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:213)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at com.atlassian.seraph.filter.LoginFilter.doFilter(Unknown Source)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:213)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:265)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:505)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:212)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:505)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:203)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:505)
at com.iplanet.ias.web.connector.nsapi.NSAPIProcessor.process(NSAPIProcessor.java:157)
at com.iplanet.ias.web.WebContainer.service(WebContainer.java:598)