openam做distributed authentication(分布式认证，是这样翻译吧)遇到问题

测试这个跳转“http://dmz.titan.co.nz:10080/openam-distauth/UI/Login?goto=http://apache.titan.co.nz/xampp/phpinfo.php”
其他都按书上配置好了，出现以下错误：
type Exception report

message DistAuthConfiguratorFilter.doFilter

description The server encountered an internal error that prevented it from fulfilling this request.

exception

javax.servlet.ServletException: DistAuthConfiguratorFilter.doFilter
com.sun.identity.distauth.setup.DistAuthConfiguratorFilter.doFilter(DistAuthConfiguratorFilter.java:104)
root cause

javax.servlet.ServletException: Servlet execution threw an exception
org.forgerock.openam.validation.ResponseValidationFilter.doFilter(ResponseValidationFilter.java:44)
com.sun.identity.distauth.setup.DistAuthConfiguratorFilter.doFilter(DistAuthConfiguratorFilter.java:101)
root cause

java.lang.NoClassDefFoundError: Could not initialize class com.sun.identity.authentication.client.AuthClientUtils
com.sun.identity.authentication.distUI.LoginServlet.initializeRequestContext(LoginServlet.java:115)
com.iplanet.jato.ApplicationServletBase.processRequest(ApplicationServletBase.java:578)
com.iplanet.jato.ApplicationServletBase.doGet(ApplicationServletBase.java:459)
javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
javax.servlet.http.HttpServlet.service(HttpServlet.java:723)
org.forgerock.openam.validation.ResponseValidationFilter.doFilter(ResponseValidationFilter.java:44)
com.sun.identity.distauth.setup.DistAuthConfiguratorFilter.doFilter(DistAuthConfiguratorFilter.java:101)
note The full stack trace of the root cause is available in the Apache Tomcat/6.0.37 logs.