>BTW MS SQL 2000 SP 4 bug
>-- I did run this example and validated the erroneous result
>declare @n nvarchar(4000)
>set @n = replicate(N'z',3999)+N'i'
>select right(replace(@n, N'i', N'B'),1) -- display i but this is incorrect result, correct result is B
>

I can repro this bug. Did you check if it still exists in SQL 2005?