Invalid Cursor State Error C# DB2

Question

I run a standard query against a DB2 database with C# ADO.NET OleDb and using statements and get System.Data.OleDb.OleDbException (0x80004005): CLI0115E Invalid cursor state. SQLSTATE=24000 When I include the dispose methods for each OleDb object, the query runs. Why does this fail without the Dispose methods? From everything i have researched the using statements should dispose of the objects for me. I am using .NET 4.5.1

using (OleDbConnection conn = DBConn.BIPSConn)
{
    using (OleDbCommand cmd = new OleDbCommand(query, conn))
    {
        using (OleDbDataReader rdr = cmd.ExecuteReader())
        {
            while (rdr.Read())
            {
               string orderNumber = rdr.GetString(0).Trim();
               string originCode = rdr.GetString(1).Trim();
               string destinationCode = rdr.GetString(3).Trim();

               Record record = new Record(orderNumber, originCode, destinationCode);
               RecordList.Add(record);                                             
           }
           // for unknown reasons, without these dispose methods we get an Invalid Cursor State error
           rdr.Dispose();
        }
        cmd.Dispose();
    } 
    conn.Dispose();
}

Answer 1

You have a using block -- you don't want to call Dispose() you want to call Close(). The using block will take care of the dispose. Add in a call to Close instead.