ORA-03113 in spatial query with xmlReader

Question

I run a spatial query with xmlReader. but it occurs a ORA-03113 exception. If i use the OracleDataReader,not through xml, the execution is ok. But i have to get the geometry data through xml. I have try to set the validate connection to True, but it seems useless.
Can some one help me?Thx a lots.
Here is my code:
     string id = "scott";
     string psw = "tiger";
     string source = "Oracle";
     string connectionstring = "User Id="+id+";password="+psw+";data source="+source+";validate connection=true";
     string sql ="select cname from L218 where sdo_relate(L218.GEOLOC,MDSYS.SDO_geometry(2003,NULL,NULL,MDSYS.SDO_elem_info_array(1,1003,3),MDSYS.SDO_ordinate_array(295596.60260187,2761786.9958782, 316370.598147679,2789383.2780762)),'mask=anyinteract')='TRUE'";
     try
          Oracle.DataAccess.Client.OracleConnection con = new OracleConnection(connectionstring);
          con.Open();
          Oracle.DataAccess.Client.OracleCommand cmd = con.CreateCommand();
          cmd.XmlCommandType = OracleXmlCommandType.Query;
          cmd.BindByName = true;
          cmd.CommandText =sql;
          XmlReader xmlReader = cmd.ExecuteXmlReader();
          XmlDocument xmlDocument = new XmlDocument();
          xmlDocument.PreserveWhitespace = false;
          xmlDocument.Load(xmlReader);
          Console.WriteLine(xmlDocument.OuterXml);
          con.Close();
     catch (OracleException e)
          Console.WriteLine(e);
And it returns:
Oracle.DataAccess.Client.OracleException ORA-03113: end-of-file on communication
channel at Oracle.DataAccess.Client.OracleCommand.XmlHandleException(OracleE
xception e)
at Oracle.DataAccess.Client.OracleCommand.ExecuteXmlQuery(Boolean wantResult)
at Oracle.DataAccess.Client.OracleCommand.ExecuteXmlReader()

Answer 1

Hi Daniel
I ran the validation and some of the geometries were invalid. I have now corrected these and all are OK. The db version is 817. However, I am still getting the same error. It appears to be dependant on what cordinates the query is searching:
Errors
SELECT 1
FROM wpe_misc_site, WPE_PLAN_APPLICATION
WHERE wpe_misc_site.ste_id > 0
AND WPE_PLAN_APPLICATION.APL_ste_id(+) =
wpe_misc_site.ste_id
AND mdsys.sdo_relate(ste_geometry,
MDSYS.SDO_GEOMETRY(2003, 81989, NULL,
MDSYS.SDO_ELEM_INFO_ARRAY(1,1003,3),
MDSYS.SDO_ORDINATE_ARRAY(278792,187310,278876,187393)),
'mask=anyinteract querytype=window') = 'TRUE';
Substriute those coordinates for 278792,187308,278876,187393 and query works.
Any ideas??
Thanks
Chris