XWiki Statistics exceptions

12:29:26,367 ERROR http-10080-Processor15 http://www.xwiki.org/xwiki/bin/view/AdminGuide/Configuration AbstractFlushingEventListener:performExecutions:299 - Could not synchronize database state with session
org.hibernate.StaleStateException: Batch update returned unexpected row count from update: 0 actual row count: 0 expected: 1
at org.hibernate.jdbc.BatchingBatcher.checkRowCount(BatchingBatcher.java:93)
at org.hibernate.jdbc.BatchingBatcher.checkRowCounts(BatchingBatcher.java:79)
at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:58)
at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:195)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:230)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:145)
at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:296)
at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:27)
at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1009)
at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:356)
at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:106)
at com.xpn.xwiki.store.XWikiHibernateBaseStore.endTransaction(XWikiHibernateBaseStore.java:611)
at com.xpn.xwiki.store.XWikiHibernateBaseStore.endTransaction(XWikiHibernateBaseStore.java:585)
at com.xpn.xwiki.store.XWikiHibernateStore.deleteXWikiCollection(XWikiHibernateStore.java:859)
at com.xpn.xwiki.stats.impl.XWikiStatsServiceImpl.notify(XWikiStatsServiceImpl.java:219)
at com.xpn.xwiki.notify.XWikiActionRule.verify(XWikiActionRule.java:59)
at com.xpn.xwiki.notify.XWikiNotificationManager.verify(XWikiNotificationManager.java:143)
at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:210)
at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:414)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:689)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)