Ok... after several hours I think I've finally answered my own question The two versions of the SSO package (source and binary-only) are DIFFERENT - the version of jboss-sso-tomcat5.jar in the binary download doesnt have PlainAutoSSOLogout.class but the version in the older, source does (as do the the versions in the Seam hotels and DVD demos). I'm now using the version from the source download and have now gone past the stage of this classloader error. The binary version is JBoss Federated SSO - 1.0.0.Beta-Update 1 size 10 MB dated 12/7/06 | | jar file - 01/11/2006 06:18 10,589 jboss-sso-tomcat5.jar | | jar contents | META-INF/ | META-INF/MANIFEST.MF | org/ | org/jboss/ | org/jboss/security/ | org/jboss/security/valve/ | org/jboss/security/valve/SSOAutoLogin.class | org/jboss/security/valve/SSOAutoLogout.class | org/jboss/security/valve/SSOSession.class | org/jboss/security/valve/SSOTokenManager.class | and the source is | JBoss Federated SSO - 1.0.0.Beta-Update 1 size 44 MB dated 11/20/06 | | jar file - 21/11/2006 00:05 19,028 jboss-sso-tomcat5.jar | | jar contents | META-INF/ | META-INF/MANIFEST.MF | org/ | org/jboss/ | org/jboss/security/ | org/jboss/security/valve/ | org/jboss/security/valve/PlainSSOAutoLogin.class | org/jboss/security/valve/PlainSSOAutoLogout.class | org/jboss/security/valve/PlainSSOTokenManager.class | org/jboss/security/valve/SSOAutoLogin.class | org/jboss/security/valve/SSOAutoLogout.class | org/jboss/security/valve/SSOSession.class | org/jboss/security/valve/SSOTokenManager.class | Just to make things 'interesting', there are a number of differences in the two versions where it appears that the binary version is more up-to-date. e.g from the binary download public LDAPIdentityProvider(String id, Properties properties) | source download public LDAPIdentityProvider() [rant mode]Ok, I know this is still in beta but it would be nice if the distributions were consistent with each other rather than me wasting hours of my time debugging them[/rant mode] :-) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3992810#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...