Nice to see someone using LOGs. But I would trust your results more if you displayed them, instead of using the WHERE expected_result <> actual_result.
The problem I found was that you don't get exact representation when using float. Frankly, I have never used float before, so maybe I am doing something incorrectly, but note the example below.
declare @num float
, @res float
, @digits int
SET @num = 1.23456678
SET @digits = 4
select @res = case when @num > 0
select @num as ORIGINAL_NUMBER, @res AS RESULT
, @digits as NBR_SIG_DIGITS
ORIGINAL_NUMBER RESULT NBR_SIG_DIGITS
1.23456678 1.2349999999999999 4
Probably not what you really want (I assume you want 1.235 ??)