RSS access raises an error with Websphere 6.0

When I access an RSS, Confluence crashes with the following traces in the logs:

[3/11/08 17:11:16:148 CET] 00000035 ServletDispat E com.opensymphony.webwork.dispatcher.ServletDispatcher serviceAction Could not execute acti

on

com.atlassian.core.exception.InfrastructureException: java.lang.VerifyError: (class: com/sun/syndication/io/i

mpl/RSS090Generator, method: populateItem signature: (Lcom/sun/syndication/feed/rss/Item;Lorg/jdom/Element;I)V) Incompatible argument to funct

ion

at com.atlassian.xwork.interceptors.XWorkTransactionInterceptor.intercept(XWorkTransactionInterceptor.java:116)

at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:165)

at com.opensymphony.xwork.interceptor.AroundInterceptor.intercept(AroundInterceptor.java:35)

at com.opensymphony.xwork.DefaultActionInvocation.invoke(DefaultActionInvocation.java:165)

at com.opensymphony.xwork.DefaultActionProxy.execute(DefaultActionProxy.java:115)

at com.opensymphony.webwork.dispatcher.ServletDispatcher.serviceAction(ServletDispatcher.java:229)

at com.opensymphony.webwork.dispatcher.ServletDispatcher.service(ServletDispatcher.java:199)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:856)

at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:1572)

at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:1521)

at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:136)

at com.ibm.ws.xd.webcontainer.extensions.RebalancerFilter.doFilter(RebalancerFilter.java:230)

at com.ibm.ws.webcontainer.filter.FilterInstanceWrapper.doFilter(FilterInstanceWrapper.java:142)

at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:121)

at com.opensymphony.module.sitemesh.filter.PageFilter.parsePage(PageFilter.java:118)

at com.atlassian.confluence.util.profiling.ProfilingPageFilter.parsePage(ProfilingPageFilter.java:124)

at com.opensymphony.module.sitemesh.filter.PageFilter.doFilter(PageFilter.java:54)

at com.ibm.ws.webcontainer.filter.FilterInstanceWrapper.doFilter(FilterInstanceWrapper.java:142)

at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:121)

at com.atlassian.core.filters.ServletContextThreadLocalFilter.doFilter(ServletContextThreadLocalFilter.java:21)

at com.ibm.ws.webcontainer.filter.FilterInstanceWrapper.doFilter(FilterInstanceWrapper.java:142)

at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:121)

at com.atlassian.confluence.util.LoggingContextFilter.doFilter(LoggingContextFilter.java:49)

at com.ibm.ws.webcontainer.filter.FilterInstanceWrapper.doFilter(FilterInstanceWrapper.java:142)

at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:121)

at com.atlassian.confluence.util.UserThreadLocalFilter.doFilter(UserThreadLocalFilter.java:44)

at com.ibm.ws.webcontainer.filter.FilterInstanceWrapper.doFilter(FilterInstanceWrapper.java:142)

at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:121)

at com.atlassian.seraph.filter.SecurityFilter.doFilter(SecurityFilter.java:192)

at com.ibm.ws.webcontainer.filter.FilterInstanceWrapper.doFilter(FilterInstanceWrapper.java:142)

at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:121)

at com.atlassian.seraph.filter.TrustedApplicationsFilter.doFilter(TrustedApplicationsFilter.java:112)

at com.atlassian.confluence.util.AbstractBootstrapHotSwappingFilter.doFilter(AbstractBootstrapHotSwappingFilter.java:28)

at com.ibm.ws.webcontainer.filter.FilterInstanceWrapper.doFilter(FilterInstanceWrapper.java:142)

Issue has been solved with the following procedure:
1) deploy with the "Parent _last" class loader option, so that, in case of conflict between a class in Websphere and a class in Confluence, Confluence class be used
2) remove the cglib-1.0.jar from Confluence (crashes the application otherwise)