View SELECT Differences Between SQL 2000 && 2005

I have the following a view on a SQL2K box that uses the following SELECT statement:

SELECT



SF.SKU,
SAT.PublicationDate AS SATPubDate,
SAM.PublicationDate AS SAMPubDat
FROM SkuFlags SF
LEFT OUTER JOIN SpringArbor_ttlsparb SAT ON SF.ISBN = SAT.ISBN
LEFT OUTER JOIN SpringArbor_music SAM ON SF.ISBN = SAM.PrimaryKey
WHERE (
(
( SAT.PublicationDate IS NOT NULL ) AND
( SAT.PublicationDate <> '010001' ) AND
( GETDATE() <= DATEADD(day, -1, ( CAST(LEFT(SAT.PublicationDate, 2) + '/01/' + RIGHT(SAT.PublicationDate, 4) AS DATETIME) )))
)
OR (
( SAM.PublicationDate <> '010001' ) AND
( SAM.PublicationDate IS NOT NULL ) AND
( GETDATE() <= DATEADD(day, -1, ( CAST(LEFT(SAM.PublicationDate, 2) + '/01/' + RIGHT(SAM.PublicationDate, 4) AS DATETIME)))
)
)


The view works in SQL2K. When I try to run it under SQL2K5, I get a "The conversion of a char data type to a datetime data type resulted in an out-of-range datetime value." error. I know what the error is, the SAM.PublicationDate field has NULL values in it (and this is vendor supplied data that is updated frequently, so not dealing with NULL values isn't an option), so during the CAST function it's try to CAST NULL + /01/ + NULL into a DATETIME value and crashing.

My question is why this works in SQL2K and not SQL2K5?

Thanks,
Kevin