Frequent problems communicating with server on my LAN.

Exception:

java.nio.BufferUnderflowException
at java.nio.Buffer.nextGetIndex(Unknown Source)
at java.nio.HeapByteBuffer.get(Unknown Source)
at com.zimbra.cs.mailclient.imap.MailboxName.decodePE M(MailboxName.java:105)
at com.zimbra.cs.mailclient.imap.MailboxName.decodeBy tes(MailboxName.java:75)
at com.zimbra.cs.mailclient.imap.MailboxName.decode(M ailboxName.java:60)
at com.zimbra.cs.mailclient.imap.MailboxName.decode(M ailboxName.java:56)
at com.zimbra.cs.mailclient.imap.ListData.readMailbox List(ListData.java:72)
at com.zimbra.cs.mailclient.imap.ListData.read(ListDa ta.java:47)
at com.zimbra.cs.mailclient.imap.ImapResponse.readUnt agged(ImapResponse.java:92)
at com.zimbra.cs.mailclient.imap.ImapResponse.readRes ponse(ImapResponse.java:53)
at com.zimbra.cs.mailclient.imap.ImapResponse.read(Im apResponse.java:41)
at com.zimbra.cs.mailclient.imap.ImapConnection.readR esponse(ImapConnection.java:628)
at com.zimbra.cs.mailclient.imap.ImapConnection.nextR esponse(ImapConnection.java:622)
at com.zimbra.cs.mailclient.imap.ImapConnection.waitF orResponse(ImapConnection.java:541)
at com.zimbra.cs.mailclient.imap.ImapConnection.sendR equest(ImapConnection.java:475)
at com.zimbra.cs.mailclient.imap.ImapRequest.send(Ima pRequest.java:77)
at com.zimbra.cs.mailclient.imap.ImapRequest.sendChec kStatus(ImapRequest.java:81)
at com.zimbra.cs.mailclient.imap.ImapConnection.doLis t(ImapConnection.java:267)
at com.zimbra.cs.mailclient.imap.ImapConnection.list( ImapConnection.java:251)
at com.zimbra.cs.datasource.ImapUtil.listFolders(Imap Util.java:47)
at com.zimbra.cs.datasource.ImapSync.syncFolders(Imap Sync.java:193)
at com.zimbra.cs.datasource.ImapSync.importData(ImapS ync.java:152)
at com.zimbra.cs.offline.OfflineImport.importData(Off lineImport.java:88)
at com.zimbra.cs.datasource.DataSourceManager.importD ata(DataSourceManager.java:154)
at com.zimbra.cs.mailbox.LocalMailbox.importData(Loca lMailbox.java:417)
at com.zimbra.cs.mailbox.LocalMailbox.syncAllLocalDat aSources(LocalMailbox.java:389)
at com.zimbra.cs.mailbox.LocalMailbox.sync(LocalMailb ox.java:431)
at com.zimbra.cs.mailbox.LocalMailbox.syncOnTimer(Loc alMailbox.java:361)
at com.zimbra.cs.mailbox.DesktopMailbox$1.run(Desktop Mailbox.java:437)
at java.util.TimerThread.mainLoop(Unknown Source)
at java.util.TimerThread.run(Unknown Source)