I have a client that is intermittently receiving soap errors..
This is the trace from the most recent. If any one has any idea what this means i would greatly appreciate it . He was sending a .pdf if that is relevant
Thanks in advance.

<SyncError><Request><soap:Envelope xmlns:soap="http://www.w3.org/2003/05/soap-envelope"><soap:Header><context xmlns="urn:zimbra"><userAgent name="ZimbraConnectorForOutlook" version="6.0.6058.8"/><nonotify/><noqualify/><account by="id">1be4e874-534d-4e93-ab36-5fe5aa4152ef</account><authToken>0_23fb64762ec21c6e008fca4ddaab7 abbd2541965_69643d33363a31626534653837342d35333464 2d346539332d616233362d3566653561613431353265663b65 78703d31333a313330383835303538393237313b747970653d 363a7a696d6272613b</authToken><nosession/></context></soap:Header><soap:Body><SaveDraftRequest xmlns="urn:zimbraMail"><m aid="6e6211ca-1827-409c-af56-b67d69c63156:2cf4ed23-80a0-4999-abc8-aca6e51e8d45" id="7200"/></SaveDraftRequest></soap:Body></soap:Envelope></Request><Response><soap:Envelope xmlns:soap="http://www.w3.org/2003/05/soap-envelope"><soap:Header><context xmlns="urn:zimbra"><change token="37866"/></context></soap:Header><soap:Body><soap:Fault><soap:Code><soa p:Value>soap:Sender</soap:Value></soap:Code><soap:Reason><soap:Text>cannot modify immutable object: 7200</soap:Text></soap:Reason><soapetail><Error xmlns="urn:zimbra"><Code>mail.IMMUTABLE_OBJECT</Code><Trace>com.zimbra.cs.mailbox.MailServiceExcep tion: cannot modify immutable object: 7200
ExceptionId:btpool0-316://zimbra.4kenrich.com/service/soap/SaveDraftRequest:1308677868122:b2f2cbcf782faeab
Code:mail.IMMUTABLE_OBJECT ArgitemId, IID, "7200")
at com.zimbra.cs.mailbox.MailServiceException.IMMUTAB LE_OBJECT(MailServiceException.java:379)
at com.zimbra.cs.mailbox.Mailbox.saveDraft(Mailbox.ja va:4822)
at com.zimbra.cs.service.mail.SaveDraft.handle(SaveDr aft.java:116)
at com.zimbra.soap.SoapEngine.dispatchRequest(SoapEng ine.java:420)
at com.zimbra.soap.SoapEngine.dispatch(SoapEngine.jav a:274)
at com.zimbra.soap.SoapEngine.dispatch(SoapEngine.jav a:158)
at com.zimbra.soap.SoapServlet.doWork(SoapServlet.jav a:291)
at com.zimbra.soap.SoapServlet.doPost(SoapServlet.jav a:212)
at javax.servlet.http.HttpServlet.service(HttpServlet .java:727)
at com.zimbra.cs.servlet.ZimbraServlet.service(Zimbra Servlet.java:181)
at javax.servlet.http.HttpServlet.service(HttpServlet .java:820)
at org.mortbay.jetty.servlet.ServletHolder.handle(Ser vletHolder.java:511)
at org.mortbay.jetty.servlet.ServletHandler$CachedCha in.doFilter(ServletHandler.java:1166)
at com.zimbra.cs.servlet.SetHeaderFilter.doFilter(Set HeaderFilter.java:79)
at org.mortbay.jetty.servlet.ServletHandler$CachedCha in.doFilter(ServletHandler.java:1157)
at org.mortbay.servlet.UserAgentFilter.doFilter(UserA gentFilter.java:81)
at org.mortbay.servlet.GzipFilter.doFilter(GzipFilter .java:155)
at org.mortbay.jetty.servlet.ServletHandler$CachedCha in.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler.handle(Se rvletHandler.java:388)
at org.mortbay.jetty.security.SecurityHandler.handle( SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(Se ssionHandler.java:182)
at org.mortbay.jetty.handler.ContextHandler.handle(Co ntextHandler.java:765)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebA ppContext.java:418)
at org.mortbay.jetty.handler.ContextHandlerCollection .handle(ContextHandlerCollection.java:230)
at org.mortbay.jetty.handler.HandlerCollection.handle (HandlerCollection.java:114)
at org.mortbay.jetty.handler.HandlerWrapper.handle(Ha ndlerWrapper.java:152)
at org.mortbay.jetty.handler.rewrite.RewriteHandler.h andle(RewriteHandler.java:230)
at org.mortbay.jetty.handler.HandlerWrapper.handle(Ha ndlerWrapper.java:152)
at org.mortbay.jetty.handler.DebugHandler.handle(Debu gHandler.java:77)
at org.mortbay.jetty.handler.HandlerWrapper.handle(Ha ndlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(Htt pConnection.java:543)
at org.mortbay.jetty.HttpConnection$RequestHandler.co ntent(HttpConnection.java:939)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser. java:755)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpPa rser.java:218)
at org.mortbay.jetty.HttpConnection.handle(HttpConnec tion.java:405)
at org.mortbay.io.nio.SelectChannelEndPoint.run(Selec tChannelEndPoint.java:413)
at org.mortbay.thread.BoundedThreadPool$PoolThread.ru n(BoundedThreadPool.java:451)
</Trace><a t="IID" n="itemId">7200</a></Error></soapetail></soap:Fault></soap:Body></soap:Envelope></Response></SyncError>