CRJAZ6001E: Change events could not be processed because an error occurred during processing

On our jts server we have every once in a while a strange problem with the jts server. We are at 4.0.2 and the error in the jts.log is
2014-01-31 01:33:29,618 [ jts: AsynchronousTaskRunner-3]  WARN m.team.repository.service.internal.LogFeedAppender  - CRJAZ0994W Failed to write log event to disk.
2014-01-31 01:33:34,109 [ jts: AsynchronousTaskRunner-3] ERROR com.ibm.team.process                                - CRJAZ6001E: Change events could not be processed because an error occurred during processing.
com.ibm.team.repository.common.InternalRepositoryException: CRJAZ0368I A SQL query failed to execute properly on the server.
   stmt = select t1.ITEM_ID, t1.STATE_ID from PROCESS.PROCESS_CHANGE_EVENT_CHECK t1
    at com.ibm.team.repository.service.internal.dataaccess.FetchRows.executeQuery(FetchRows.java:253)
    at com.ibm.team.repository.service.internal.dataaccess.QueryFetchRows.next(QueryFetchRows.java:77)
    at com.ibm.team.repository.service.internal.dataaccess.QueryFetchRows.allData(QueryFetchRows.java:127)
    at com.ibm.team.repository.service.internal.ExecuteDataQuery.doQueryData(ExecuteDataQuery.java:124)
    at com.ibm.team.repository.service.internal.RdbRepositoryDataMediator.queryData(RdbRepositoryDataMediator.java:900)
    at com.ibm.team.repository.service.internal.AbstractQueryService.performQuery(AbstractQueryService.java:70)
    at com.ibm.team.repository.service.internal.QueryService.doExecuteItemQuery(QueryService.java:336)
    at com.ibm.team.repository.service.internal.QueryService.access$0(QueryService.java:331)
    at com.ibm.team.repository.service.internal.QueryService$1.run(QueryService.java:178)
    at com.ibm.team.repository.service.internal.QueryService$1.run(QueryService.java:1)
    at com.ibm.team.repository.service.internal.rdb.RepositoryDatabase$Transaction.run(RepositoryDatabase.java:488)
    at com.ibm.team.repository.service.internal.rdb.RepositoryDatabase$1.run(RepositoryDatabase.java:312)
    at com.ibm.team.repository.service.internal.rdb.ConnectionPoolService.withCurrentConnection(ConnectionPoolService.java:381)
    at sun.reflect.GeneratedMethodAccessor102.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37)
    at java.lang.reflect.Method.invoke(Method.java:611)
    at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.invoke(ExportProxyServiceRecord.java:361)
    at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.access$0(ExportProxyServiceRecord.java:347)
    at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord$ExportedServiceInvocationHandler.invoke(ExportProxyServiceRecord.java:56)
    at com.sun.proxy.$Proxy286.withCurrentConnection(Unknown Source)
    at com.ibm.team.repository.service.internal.rdb.RepositoryDatabase.runTransaction(RepositoryDatabase.java:308)
    at com.ibm.team.repository.service.internal.rdb.RepositoryDatabase.runInTransaction(RepositoryDatabase.java:263)
    at com.ibm.team.repository.service.internal.PrimitiveTransactionService.runInTransaction(PrimitiveTransactionService.java:110)
    at sun.reflect.GeneratedMethodAccessor117.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37)
    at java.lang.reflect.Method.invoke(Method.java:611)
    at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.invoke(ExportProxyServiceRecord.java:361)
    at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.access$0(ExportProxyServiceRecord.java:347)
    at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord$ExportedServiceInvocationHandler.invoke(ExportProxyServiceRecord.java:56)
    at com.sun.proxy.$Proxy355.runInTransaction(Unknown Source)
    at com.ibm.team.repository.service.internal.QueryService.executeItemQuery(QueryService.java:167)
    at com.ibm.team.repository.service.internal.QueryService.queryItems(QueryService.java:477)
    at sun.reflect.GeneratedMethodAccessor378.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37)
    at java.lang.reflect.Method.invoke(Method.java:611)
    at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.invoke(ExportProxyServiceRecord.java:361)
    at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.access$0(ExportProxyServiceRecord.java:347)
    at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord$ExportedServiceInvocationHandler.invoke(ExportProxyServiceRecord.java:56)
    at com.sun.proxy.$Proxy489.queryItems(Unknown Source)
    at com.ibm.team.repository.service.internal.SecureQueryService.queryItems(SecureQueryService.java:55)
    at com.ibm.team.process.internal.service.ProcessService.getEventCheck(ProcessService.java:4642)
    at com.ibm.team.process.internal.service.ProcessService.processChangeEvents(ProcessService.java:4508)
    at sun.reflect.GeneratedMethodAccessor422.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37)
    at java.lang.reflect.Method.invoke(Method.java:611)
    at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.invoke(ExportProxyServiceRecord.java:361)
    at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.access$0(ExportProxyServiceRecord.java:347)
    at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord$ExportedServiceInvocationHandler.invoke(ExportProxyServiceRecord.java:56)
    at com.sun.proxy.$Proxy662.processChangeEvents(Unknown Source)
    at com.ibm.team.process.internal.service.ProcessChangeEventsTask.runTask(ProcessChangeEventsTask.java:36)
    at com.ibm.team.repository.service.async.AbstractAutoScheduledTask.executeTask(AbstractAutoScheduledTask.java:88)
    at sun.reflect.GeneratedMethodAccessor269.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37)
    at java.lang.reflect.Method.invoke(Method.java:611)
    at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.invoke(ExportProxyServiceRecord.java:361)
    at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.access$0(ExportProxyServiceRecord.java:347)
    at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord$ExportedServiceInvocationHandler.invoke(ExportProxyServiceRecord.java:56)
    at com.sun.proxy.$Proxy665.executeTask(Unknown Source)
    at com.ibm.team.repository.service.internal.scheduler.AsynchronousTaskRunner.runTask(AsynchronousTaskRunner.java:153)
    at com.ibm.team.repository.service.internal.scheduler.AsynchronousTaskRunner.run(AsynchronousTaskRunner.java:116)
    at java.lang.Thread.run(Thread.java:773)
Caused by: com.ibm.db2.jcc.am.SqlException: DB2 SQL Error: SQLCODE=-1773, SQLSTATE=     , SQLERRMC=1, DRIVER=4.14.88
    at com.ibm.db2.jcc.am.ed.a(ed.java:682)
    at com.ibm.db2.jcc.am.ed.a(ed.java:60)
    at com.ibm.db2.jcc.am.ed.a(ed.java:127)
    at com.ibm.db2.jcc.am.ResultSet.completeSqlca(ResultSet.java:4101)
    at com.ibm.db2.jcc.am.ResultSet.earlyCloseComplete(ResultSet.java:4083)
    at com.ibm.db2.jcc.t4.ab.a(ab.java:835)
    at com.ibm.db2.jcc.t4.ab.n(ab.java:801)
    at com.ibm.db2.jcc.t4.ab.j(ab.java:253)
    at com.ibm.db2.jcc.t4.ab.d(ab.java:55)
    at com.ibm.db2.jcc.t4.p.c(p.java:44)
    at com.ibm.db2.jcc.t4.qb.j(qb.java:147)
    at com.ibm.db2.jcc.am.oo.kb(oo.java:2156)
    at com.ibm.db2.jcc.am.po.b(po.java:4462)
    at com.ibm.db2.jcc.am.po.gc(po.java:750)
    at com.ibm.db2.jcc.am.po.executeQuery(po.java:719)
    at com.ibm.team.repository.service.internal.db.jdbcwrappers.stat.PreparedStatementStatWrapper.executeQuery(PreparedStatementStatWrapper.java:60)
    at com.ibm.team.repository.service.internal.db.jdbcwrappers.errlog.PreparedStatementErrLogWrapper.executeQuery(PreparedStatementErrLogWrapper.java:78)
    at com.ibm.team.repository.service.internal.db.jdbcwrappers.leak.PreparedStatementLeakWrapper.executeQuery(PreparedStatementLeakWrapper.java:57)
    at com.ibm.team.repository.service.internal.dataaccess.FetchRows.executeQuery(FetchRows.java:225)
    ... 60 more

Is there something that needs to be changed ? We are this problem also at night, when no user works on the system.