Error "Conversion failed when converting date and/or time from character string" to execute one query in sql 2008 r2, run ok in 2005.

Question

I have  a table-valued function that run in sql 2005 and when try to execute in sql 2008 r2, return the next "Conversion failed when converting date and/or time from character string".
USE [Runtime]
GO
/****** Object:  UserDefinedFunction [dbo].[f_Pinto_Graf_P_Opt]    Script Date: 06/11/2013 08:47:47 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE   FUNCTION [dbo].[f_Pinto_Graf_P_Opt] (@fechaInicio datetime, @fechaFin datetime)  
-- Declaramos la tabla "@Produc_Opt" que será devuelta por la funcion
RETURNS @Produc_Opt table ( Hora datetime,NSACOS int, NSACOS_opt int)
AS  
BEGIN 
-- Crea el Cursor
DECLARE cursorHora CURSOR
READ_ONLY
FOR SELECT DateTime, Value FROM f_PP_Graficas ('Pinto_CON_SACOS',@fechaInicio, @fechaFin,'Pinto_PRODUCTO')
-- Declaracion de variables locales
DECLARE @produc_opt_hora int
DECLARE @produc_opt_parc int
DECLARE @nsacos int
DECLARE @time_parc datetime
-- Inicializamos VARIABLES
SET @produc_opt_hora = (SELECT * FROM f_Valor (@fechaFin,'Pinto_PRODUC_OPT'))
-- Abre y se crea el conjunto del cursor
OPEN cursorHora
-- Comenzamos los calculos 
FETCH NEXT FROM cursorHora INTO @time_parc,@nsacos
/************  BUCLE WHILE QUE SE VA A MOVER A TRAVES DEL CURSOR  ************/
WHILE (@@fetch_status <> -1)
BEGIN
IF (@@fetch_status = -2)
BEGIN
-- Terminamos la ejecucion 
BREAK
END
-- REALIZAMOS CÁLCULOS
SET @produc_opt_parc = (SELECT dbo.f_P_Opt_Parc (@fechaInicio,@time_parc,@produc_opt_hora))
-- INSERTAMOS VALORES EN LA TABLA
INSERT @Produc_Opt VALUES (@time_parc,@nsacos, @produc_opt_parc)
-- Avanzamos el cursor
FETCH NEXT FROM cursorHora INTO @time_parc,@nsacos
END
/************  FIN DEL BUCLE QUE SE MUEVE A TRAVES DEL CURSOR  ***************/
-- Cerramos el cursor
CLOSE cursorHora
-- Liberamos  los cursores
DEALLOCATE cursorHora
RETURN 
END

Answer 1

You can search the forums for that error message and find previous discussions - they all boil down to the same problem.  Somewhere in your query that calls this function, the code invoked implicitly converts from string to date/datetime.  In general,
this works in any version of sql server if the runtime settings are correct for the format of the string data.  The fact that it works in one server and not in another server suggests that the query executes with different settings - and I'll assume for
the moment that the format of the data involved in this conversion is consistent within the database/resultset and consistent between the 2 servers. 
I suggest you read Tibor's guide to the datetime datatype (via the link to his site below) first - then go find the actual code that performs this conversion.  It may not be in the function you posted, since that function also executes other functions. 
You also did not post the query that calls this function, so this function may not, in fact, be the source of the problem at all. 
Tibor's site