Split Function To Separate Comma Delimited Values Into A Table

I have a stored procedure that is passed two values. Both are strings representations of GUID values, the first is a single value, the second is a comma delimited string of values.In the stored procedure I call a split function to separate the comma delimited values into a table and this is used in my WHERE clause to filter my select results.This is an example:

Code:
SELECT
item.uiGUID as ItemGUID,
stores.strStoreName as Store,
location.strLocationName as Location
FROM tblItems as item
INNER JOIN tblStoreLocations as location
ON item.uiLocationGUID = location.uiGUID
INNER JOIN tblStores as stores
ON location.uiStoreGUID = stores.uiGUID
WHERE CAST(item.uiGUID as varchar(36)) IN (SELECT Value FROM dbo.Split(',',@ItemGUIDList))

When I run this query in the management studio, passing a list of 5 values in the second parameter, my results include one item for each of the 5 values. However, when I pass the parameters from my ASP project, (I've verified the values I think are being passed are indeed being passed), I only get one item.I believe the error is in my split function. Both split functions return the same results in the SQL management studio, but only one returns the correct results in the the ASP project.

When I use this version of the function it returns the correct table values to the calling application, but it chokes when the item list does not have a trailing comma. I figure that to be a bug in the SQL function.

Code:
CREATE FUNCTION [dbo].[Split]
( @Delimiter varchar(5),
@List varchar(8000)
)
RETURNS @TableOfValues table
( RowID smallint IDENTITY(1,1),
[Value] varchar(50)

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