I have this stored procedure:

CREATE OR REPLACE PROCEDURE "LIQUIDACION_OBTENER" (
  p_Cuenta IN NUMBER, 
  p_Fecha IN DATE,
  p_Detalle OUT LIQUIDACION.FILADETALLE%TYPE
) IS

BEGIN 

  SELECT FILADETALLE
    INTO p_Detalle
    FROM Liquidacion
   WHERE (FILACUENTA = p_Cuenta)
     AND (FILAFECHA = p_Fecha);

END;
/

...and my c# code:

string liquidacion = string.Empty;

OracleCommand command = new OracleCommand("Liquidacion_Obtener");            

command.BindByName = true;
command.Parameters.Add(new OracleParameter("p_Cuenta", OracleDbType.Int64));
command.Parameters["p_Cuenta"].Value = cuenta;
command.Parameters.Add(new OracleParameter("p_Fecha", OracleDbType.Date));
command.Parameters["p_Fecha"].Value = fecha;

command.Parameters.Add("p_Detalle", OracleDbType.Varchar2, ParameterDirection.Output);            

OracleConnectionHolder connection = null;

connection = this.GetConnection();
command.Connection = connection.Connection;
command.CommandTimeout = 30;
command.CommandType = CommandType.StoredProcedure;
OracleDataReader lector = command.ExecuteReader();

while (lector.Read())
{
    liquidacion += ((OracleString)command.Parameters["p_Detalle"].Value).Value;
}

the thing is that when I try to put a value into the parameter "Fecha" (that is a date) the code gives me this error (when the line command.ExecuteReader(); is executed)

Oracle.DataAccess.Client.OracleException : ORA-06502: PL/SQL: numeric or value error
ORA-06512: at "SYSTEM.LIQUIDACION_OBTENER", line 9
ORA-06512: at line 1

I tried with the datetime and was not the problem, I eve tried with no input parameters and just the output and still got the same error. Aparently the problem is with the output parameter. I already tried putting p_Detalle OUT VARCHAR2 instead of p_Detalle OUT LIQUIDACION.FILADETALLE%TYPE but it didn't work either

I hope my post is understandable.. thanks!!!!!!!!!!