title: SQL Navigator throws 'ORA-01834: Not a valid month' but query runs in other applications
body: <p>I have stocked in this error many times but know I have no way to avoid and I have to get rid of it.</p>
  
  <p>Sometimes I do run a query in <code>SQL Navigator 6.1 XPert Edition</code> and it throws:</p>
  
  <p><code>ORA-01843: Not a valid month</code></p>
  
  <p>But if I run this same query in same database but in other application(ie <code>Aqua Data Studio</code>) it works fine. It's just in isolated cases.</p>
  
  <p>It may be some config problem? </p>
  
  <p><strong>EDIT: This query has that problem:</strong></p>
  
  <pre><code>            select
                  quantity dias_a_vencer
                  , estab
                  , initcap (planejador) planejador
                  , atributo2 fabrica
                  , mrp.item montagem
                  , initcap (descricao) des_montagem
                  , mrp.nro_docmto num_of
                  , initcap (mrp.fornecedor) cliente
                  , mrp.project_number projeto
                  , initcap (comprador) processista
                  , trunc (mrp.data_inicio) data_inicio
              from etlt_mrp_exceptions mrp
              where 
                  mrp.compile_designator = 'ENGI'
                  and mrp.dt_coleta &gt; sysdate - 50
                  and estab = '179'        -- PARAMETRO ESTAB FILTRO
                  and atributo2 = '11'   -- PARAMETRO FABRICA FILTRO
                  and nvl (mrp.quantity, 0) &gt; 0
                  and dt_coleta = '05/12/2011'                         -- parametro do grafico acima
                  and initcap (planejador) = 'Maria Cristina Da Cruz Costa'        -- parametro do grafico acima
              order by quantity
              , des_montagem
  </code></pre>