Hi, I have migrated ZCS from 5.0.0 to 6.0.4 because problem with expired certificate.Update OK but everyday I see this error in mailbox.log:

ExceptionId:ImapServer-451:1265692502080:a37136480a29dcce
Code:service.FAILURE
at com.zimbra.common.service.ServiceException.FAILURE (ServiceException.java:247)
at com.zimbra.cs.account.ldap.ZimbraLdapContext.<init >(ZimbraLdapContext.java:394)
at com.zimbra.cs.account.ldap.ZimbraLdapContext.<init >(ZimbraLdapContext.java:355)
at com.zimbra.cs.account.ldap.LdapProvisioning.getAcc ountByQuery(LdapProvisioning.java:584)
at com.zimbra.cs.account.ldap.LdapProvisioning.getAcc ountByNameInternal(LdapProvisioning.java:758)
at com.zimbra.cs.account.ldap.LdapProvisioning.getAcc ountByName(LdapProvisioning.java:736)
at com.zimbra.cs.account.ldap.LdapProvisioning.get(Ld apProvisioning.java:644)
at com.zimbra.cs.account.ldap.LdapProvisioning.get(Ld apProvisioning.java:629)
at com.zimbra.cs.security.sasl.PlainAuthenticator.aut henticate(PlainAuthenticator.java:85)
at com.zimbra.cs.imap.ImapHandler.authenticate(ImapHa ndler.java:1160)
at com.zimbra.cs.imap.ImapHandler.doLOGIN(ImapHandler .java:1123)
at com.zimbra.cs.imap.ImapHandler.executeRequest(Imap Handler.java:456)
at com.zimbra.cs.imap.TcpImapHandler.processCommand(T cpImapHandler.java:99)
at com.zimbra.cs.tcpserver.ProtocolHandler.processCon nection(ProtocolHandler.java:175)
at com.zimbra.cs.tcpserver.ProtocolHandler.run(Protoc olHandler.java:132)
at EDU.oswego.cs.dl.util.concurrent.PooledExecutor$Wo rker.run(Unknown Source)
at java.lang.Thread.run(Thread.java:619)
Caused by: javax.naming.CommunicationException: Bad file descriptor [Root exception is java.net.SocketException: Bad file descriptor]
at com.sun.jndi.ldap.LdapCtx.extendedOperation(LdapCt x.java:3213)
at javax.naming.ldap.InitialLdapContext.extendedOpera tion(InitialLdapContext.java:164)
at com.zimbra.cs.account.ldap.ZimbraLdapContext.<init >(ZimbraLdapContext.java:384)
... 15 more
Caused by: java.net.SocketException: Bad file descriptor
at java.net.SocketOutputStream.socketWrite0(Native Method)
at java.net.SocketOutputStream.socketWrite(SocketOutp utStream.java:92)
at java.net.SocketOutputStream.write(SocketOutputStre am.java:136)
at java.io.BufferedOutputStream.flushBuffer(BufferedO utputStream.java:65)
at java.io.BufferedOutputStream.flush(BufferedOutputS tream.java:123)
at com.sun.jndi.ldap.Connection.writeRequest(Connecti on.java:393)
at com.sun.jndi.ldap.LdapClient.extendedOp(LdapClient .java:1172)
at com.sun.jndi.ldap.LdapCtx.extendedOperation(LdapCt x.java:3160)
... 17 more

and I have to restart ZCS services.

I have increased file descriptors like Bug 42870 , but it doesn't works.

Please help.