Error con la funcion crosstab

Hola cuando ejecuto este query una vez funciona y otra no

ERROR EN EL LOG:
2012-02-02 11:42:49 CET LOG: proceso de servidor (PID 12556) fue
terminado por una señal 11: Segmentation fault

SQL:
SELECT mthreport.row_name[1] as trabajador, mthreport.row_name[2] as
nombre_trabajador, mthreport.row_name[3] as anyo,
jan, feb, mar, apr, may, jun, jul, aug, sep, oct, nov, dec
FROM
crosstab('
SELECT ARRAY[i.trabajador::text, i.nombre_trabajador::text,
to_char(i.anyo,''9999'')] As row_name,
CASE
WHEN i.mes = 1::int THEN ''jan''::text
WHEN i.mes = 2::int THEN ''feb''::text
WHEN i.mes = 3::int THEN ''mar''::text
WHEN i.mes = 4::int THEN ''apr''::text
WHEN i.mes = 5::int THEN ''may''::text
WHEN i.mes = 6::int THEN ''jun''::text
WHEN i.mes = 7::int THEN ''jul''::text
WHEN i.mes = 8::int THEN ''aug''::text
WHEN i.mes = 9::int THEN ''sep''::text
WHEN i.mes = 10::int THEN ''oct''::text
WHEN i.mes = 11::int THEN ''nov''::text
WHEN i.mes = 12::int THEN ''dec''::text
ELSE NULL::text
END AS mes, i.s_fichados
FROM liv_tiempos_muertos_mes i
WHERE i.anyo = 2012
',
'SELECT to_char(date ''2012-01-01'' + (n ||
''month'')::interval, ''mon'') As short_mname FROM generate_series(0,11) n')
As mthreport(row_name text[], jan int, feb int,
mar int, apr int, may int, jun int, jul int, aug int, sep int, oct int,
nov int, dec int)