When imap client connect, I see the following stacktrace:
2008-11-21 00:03:26,719 INFO [ImapServer-1] [] imap - [xx.xx.xx.xx] connected
2008-11-21 00:03:26,968 FATAL [ImapServer-1] [] system - Fatal error occurred while handling connection
java.lang.AbstractMethodError
at com.zimbra.cs.account.ldap.LdapProvisioning.valida te(LdapProvisioning.java:243)
at com.zimbra.cs.account.ldap.LdapProvisioning.modify AttrsInternal(LdapProvisioning.java:285)
at com.zimbra.cs.account.ldap.LdapProvisioning.modify Attrs(LdapProvisioning.java:268)
at com.zimbra.cs.account.ldap.LdapProvisioning.modify Attrs(LdapProvisioning.java:249)
at com.zimbra.cs.account.Provisioning.modifyAttrs(Pro visioning.java:1609)
at com.zimbra.cs.account.ldap.LdapProvisioning.update LastLogon(LdapProvisioning.java:2825)
at com.zimbra.cs.account.ldap.LdapProvisioning.authAc count(LdapProvisioning.java:2796)
at com.zimbra.cs.account.ldap.LdapProvisioning.authAc count(LdapProvisioning.java:2751)
at com.zimbra.cs.security.sasl.AuthenticatorUtil.auth enticate(AuthenticatorUtil.java:48)
at com.zimbra.cs.imap.ImapHandler.authenticate(ImapHa ndler.java:1064)
at com.zimbra.cs.imap.ImapAuthenticatorUser.authentic ate(ImapAuthenticatorUser.java:68)
at com.zimbra.cs.security.sasl.Authenticator.authenti cate(Authenticator.java:108)
at com.zimbra.cs.security.sasl.PlainAuthenticator.han dle(PlainAuthenticator.java:62)
at com.zimbra.cs.imap.ImapHandler.continueAuthenticat ion(ImapHandler.java:182)
at com.zimbra.cs.imap.ImapHandler.continueAuthenticat ion(ImapHandler.java:173)
at com.zimbra.cs.imap.TcpImapHandler.processCommand(T cpImapHandler.java:122)
at com.zimbra.cs.tcpserver.ProtocolHandler.processCon nection(ProtocolHandler.java:160)
at com.zimbra.cs.tcpserver.ProtocolHandler.run(Protoc olHandler.java:128)
at EDU.oswego.cs.dl.util.concurrent.PooledExecutor$Wo rker.run(Unknown Source)
at java.lang.Thread.run(Thread.java:595)


This is again happening
if I use the admin console to do anything hich makes an update to the server:

2008-11-21 00:40:48,575 INFO [btpool0-0] [name=admin@domain.com;mid=2;ip=xx.xx.xx.xx;ua=Zimb raWebClient - IE7 (Win);] soap - CreateAccountRequest
2008-11-21 00:40:48,577 WARN [btpool0-0] [name=admin@domain.com;mid=2;ip=xx.xx.xx.xx;ua=Zimb raWebClient - IE7 (Win);] SoapEngine - handler exception

java.lang.AbstractMethodError
at com.zimbra.cs.account.ldap.LdapProvisioning.valida te(LdapProvisioning.java:243)
at com.zimbra.cs.account.ldap.LdapProvisioning.create Account(LdapProvisioning.java:654)
at com.zimbra.cs.account.ldap.LdapProvisioning.create Account(LdapProvisioning.java:640)
at com.zimbra.cs.service.admin.CreateAccount.handle(C reateAccount.java:58)
at com.zimbra.soap.SoapEngine.dispatchRequest(SoapEng ine.java:433)
at com.zimbra.soap.SoapEngine.dispatch(SoapEngine.jav a:288)
at com.zimbra.soap.SoapEngine.dispatch(SoapEngine.jav a:167)
at com.zimbra.soap.SoapServlet.doPost(SoapServlet.jav a:269)
at javax.servlet.http.HttpServlet.service(HttpServlet .java:727)
at com.zimbra.cs.servlet.ZimbraServlet.service(Zimbra Servlet.java:189)
at javax.servlet.http.HttpServlet.service(HttpServlet .java:820)
at org.mortbay.jetty.servlet.ServletHolder.handle(Ser vletHolder.java:487)
at org.mortbay.jetty.servlet.ServletHandler$CachedCha in.doFilter(ServletHandler.java:1093)
at org.mortbay.servlet.UserAgentFilter.doFilter(UserA gentFilter.java:81)
at org.mortbay.servlet.GzipFilter.doFilter(GzipFilter .java:132)
at org.mortbay.jetty.servlet.ServletHandler$CachedCha in.doFilter(ServletHandler.java:1084)
at org.mortbay.jetty.servlet.ServletHandler.handle(Se rvletHandler.java:360)
at org.mortbay.jetty.security.SecurityHandler.handle( SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(Se ssionHandler.java:181)
at org.mortbay.jetty.handler.ContextHandler.handle(Co ntextHandler.java:716)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebA ppContext.java:406)
at org.mortbay.jetty.handler.ContextHandlerCollection .handle(ContextHandlerCollection.java:211)
at org.mortbay.jetty.handler.HandlerCollection.handle (HandlerCollection.java:114)
at org.mortbay.jetty.handler.HandlerWrapper.handle(Ha ndlerWrapper.java:139)
at org.mortbay.jetty.handler.rewrite.RewriteHandler.h andle(RewriteHandler.java:350)
at org.mortbay.jetty.handler.HandlerWrapper.handle(Ha ndlerWrapper.java:139)
at org.mortbay.jetty.Server.handle(Server.java:313)
at org.mortbay.jetty.HttpConnection.handleRequest(Htt pConnection.java:506)
at org.mortbay.jetty.HttpConnection$RequestHandler.co ntent(HttpConnection.java:844)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser. java:644)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpPa rser.java:205)
at org.mortbay.jetty.HttpConnection.handle(HttpConnec tion.java:381)
at org.mortbay.io.nio.SelectChannelEndPoint.run(Selec tChannelEndPoint.java:396)
at org.mortbay.thread.BoundedThreadPool$PoolThread.ru n(BoundedThreadPool.java:442)