Sessions on Admin Console throws Exception when under high message load

When our test server got under load and I clicked the sessions tab on the admin console, I got the following stacktrace:

java.lang.IllegalArgumentException: No enum const class org.xmpp.packet.Presence$Show.available

at java.lang.Enum.valueOf(Unknown Source)

at org.xmpp.packet.Presence$Show.valueOf(Presence.java:378)

at org.xmpp.packet.Presence.getShow(Presence.java:137)

at org.jivesoftware.openfire.admin.session_002dsummary_jsp._jspService(session_002 dsummary_jsp.java:372)

at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)

at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:487)

at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.ja va:1093)

at com.opensymphony.module.sitemesh.filter.PageFilter.parsePage(PageFilter.java:11 8)

at com.opensymphony.module.sitemesh.filter.PageFilter.doFilter(PageFilter.java:52)

at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.ja va:1084)

at org.jivesoftware.util.LocaleFilter.doFilter(LocaleFilter.java:66)

at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.ja va:1084)

at org.jivesoftware.util.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingF ilter.java:42)

at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.ja va:1084)

at org.jivesoftware.admin.PluginFilter.doFilter(PluginFilter.java:70)

at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.ja va:1084)

at org.jivesoftware.admin.AuthCheckFilter.doFilter(AuthCheckFilter.java:99)

at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.ja va:1084)

at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:360)

at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)

at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181)

at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:726)

at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:405)

at org.mortbay.jetty.handler.ContextHandlerCollection.handle(ContextHandlerCollect ion.java:206)

at org.mortbay.jetty.handler.HandlerCollection.handle(HandlerCollection.java:114)

at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)

at org.mortbay.jetty.Server.handle(Server.java:324)

at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:505)

at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.j ava:828)

at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:514)

at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:211)

at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:380)

at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:395)

at org.mortbay.thread.BoundedThreadPool$PoolThread.run(BoundedThreadPool.java:450)

Has anyone come across this at all, its happening regularly on the server. Please let me know if there is a solution to this problem… if it is a problem.