This is what i get when it trys to sync. Other PC seems to work fine.

Failure communicating with remote server. Please try again later.Debug message: resource unreachable: Internal Server Error
Exception:
com.zimbra.common.service.ServiceException: system failure: InitialSync.syncCalendarItem
ExceptionId:btpool0-0:1244845234421:a7b908e53b08d6c2
Code:service.FAILURE
at com.zimbra.common.service.ServiceException.FAILURE (ServiceException.java:253)
at com.zimbra.cs.mailbox.SyncExceptionHandler.checkRe coverableException(SyncExceptionHandler.java:40)
at com.zimbra.cs.mailbox.InitialSync.syncCalendarItem (InitialSync.java:686)
at com.zimbra.cs.mailbox.DeltaSync.deltaSync(DeltaSyn c.java:237)
at com.zimbra.cs.mailbox.DeltaSync.sync(DeltaSync.jav a:92)
at com.zimbra.cs.mailbox.DeltaSync.sync(DeltaSync.jav a:76)
at com.zimbra.cs.mailbox.MailboxSync.sync(MailboxSync .java:188)
at com.zimbra.cs.mailbox.OfflineMailbox.sync(OfflineM ailbox.java:140)
at com.zimbra.cs.service.offline.OfflineSync.handle(O fflineSync.java:47)
at com.zimbra.soap.SoapEngine.dispatchRequest(SoapEng ine.java:429)
at com.zimbra.soap.SoapEngine.dispatch(SoapEngine.jav a:286)
at com.zimbra.soap.SoapEngine.dispatch(SoapEngine.jav a:160)
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:190)
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.handle(Se rvletHandler.java:362)
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.RewriteHandler.handle(Re writeHandler.java:176)
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$RequestHandler.co ntent(HttpConnection.java:844)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser. java:644)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpPa rser.java:211)
at org.mortbay.jetty.HttpConnection.handle(HttpConnec tion.java:381)
at org.mortbay.io.nio.SelectChannelEndPoint.run(Selec tChannelEndPoint.java:396)
at org.mortbay.thread.BoundedThreadPool$PoolThread.ru n(BoundedThreadPool.java:442)
Caused by: com.zimbra.common.service.ServiceException: resource unreachable: Internal Server Error
ExceptionId:btpool0-0:1244845234421:a7b908e53b08d6c2
Code:service.RESOURCE_UNREACHABLE
at com.zimbra.common.service.ServiceException.RESOURC E_UNREACHABLE(ServiceException.java:275)
at com.zimbra.cs.service.UserServlet.doHttpOp(UserSer vlet.java:1447)
at com.zimbra.cs.service.UserServlet.getRemoteResourc e(UserServlet.java:1281)
at com.zimbra.cs.service.UserServlet.getRemoteResourc e(UserServlet.java:1274)
at com.zimbra.cs.service.UserServlet.getRemoteContent (UserServlet.java:1248)
at com.zimbra.cs.mailbox.InitialSync$RemoteInviteMime Locator.getInviteMime(InitialSync.java:115)
at com.zimbra.cs.mailbox.InitialSync.makeSetCalReques t(InitialSync.java:779)
at com.zimbra.cs.mailbox.InitialSync.syncCalendarItem (InitialSync.java:674)