Update operation rejected, data has been modified since retrieval

Hi,
On our 5.2.1 clustered server we get this error during document import
through webdav. Database is Oracle, appserver Jboss, OS sles 9
What does the "data has been modified since retrieval'" mean? I sometimes
get it too in the portal, when doing things with documents. There it does
show me a popup telling it. I don't have the problem in our similar, but non
clustered test environment.

Regards Paul


01:28:17,563 INFO [STDOUT]
EboWebdavLog|2|6/6/07|01:28:17:562|com.sssw.fw.exception.EboDataConcu rrencyException:
Update operation rejected, data has been modified since retrieval.\uA\u9at
com.sssw.fw.persist.jdbc.impl.EboJdbcDataAccessor. store(EboJdbcDataAccessor.java:1067)\uA\u9at
com.sssw.fw.persist.impl.EboPersistenceProvider.st ore(EboPersistenceProvider.java:163)\uA\u9at
com.sssw.cm.core.EboContentManager.updateFolderSiz e(EboContentManager.java:12020)\uA\u9at
com.sssw.cm.core.EboContentManager.publish(EboCont entManager.java:11256)\uA\u9at
com.sssw.cm.core.EboContentManager.doPublishConten tVersion(EboContentManager.java:6035)\uA\u9at
com.sssw.cm.core.EboContentManager.internalPublish DocContentVersion(EboContentManager.java:5941)\uA\ u9at
com.sssw.cm.core.EboContentManager.publishDocument ContentVersion(EboContentManager.java:5907)\uA\u9a t
com.sssw.cm.client.EboContentMgmtDelegate.publishD ocumentContentVersion(EboContentMgmtDelegate.java: 1859)\uA\u9at
com.sssw.webdav.method.WebdavMethod.putContent(Web davMethod.java:529)\uA\u9at
com.sssw.webdav.method.Method_PUT.executeRequest(M ethod_PUT.java:154)\uA\u9at
com.sssw.webdav.method.WebdavMethod.run(WebdavMeth od.java:213)\uA\u9at
com.sssw.webdav.WebdavServlet.service(WebdavServle t.java:295)\uA\u9at
javax.servlet.http.HttpServlet.service(HttpServlet .java:810)\uA\u9at
org.apache.catalina.core.ApplicationFilterChain.in ternalDoFilter(ApplicationFilterChain.java:252)\uA \u9at
org.apache.catalina.core.ApplicationFilterChain.do Filter(ApplicationFilterChain.java:173)\uA\u9at
org.jboss.web.tomcat.filters.ReplyHeaderFilter.doF ilter(ReplyHeaderFilter.java:96)\uA\u9at
org.apache.catalina.core.ApplicationFilterChain.in ternalDoFilter(ApplicationFilterChain.java:202)\uA \u9at
org.apache.catalina.core.ApplicationFilterChain.do Filter(ApplicationFilterChain.java:173)\uA\u9at
org.apache.catalina.core.StandardWrapperValve.invo ke(StandardWrapperValve.java:213)\uA\u9at
org.apache.catalina.core.StandardContextValve.invo ke(StandardContextValve.java:178)\uA\u9at
org.jboss.web.tomcat.security.SecurityAssociationV alve.invoke(SecurityAssociationValve.java:175)\uA\ u9at
org.jboss.web.tomcat.security.JaccContextValve.inv oke(JaccContextValve.java:74)\uA\u9at
org.apache.catalina.core.StandardHostValve.invoke( StandardHostValve.java:126)\uA\u9at
org.apache.catalina.valves.ErrorReportValve.invoke (ErrorReportValve.java:105)\uA\u9at
org.jboss.web.tomcat.tc5.jca.CachedConnectionValve .invoke(CachedConnectionValve.java:156)\uA\u9at
org.jboss.web.tomcat.tc5.sso.ClusteredSingleSignOn .invoke(ClusteredSingleSignOn.java:637)\uA\u9at
org.apache.catalina.core.StandardEngineValve.invok e(StandardEngineValve.java:107)\uA\u9at
org.apache.catalina.connector.CoyoteAdapter.servic e(CoyoteAdapter.java:148)\uA\u9at
org.apache.coyote.http11.Http11Processor.process(H ttp11Processor.java:869)\uA\u9at
org.apache.coyote.http11.Http11BaseProtocol$Http11 ConnectionHandler.processConnection(Http11BaseProt ocol.java:664)\uA\u9at
org.apache.tomcat.util.net.PoolTcpEndpoint.process Socket(PoolTcpEndpoint.java:527)\uA\u9at
org.apache.tomcat.util.net.MasterSlaveWorkerThread .run(MasterSlaveWorkerThread.java:112)\uA\u9at
java.lang.Thread.run(Thread.java:534)\uA