Doing INTERVAL with NOW() versus casted timestamp

Why does this give me two different results? 'created' is a date field:

SELECT * FROM foo WHERE created >= '2013-02-16 00:00:00'::timestamp -
INTERVAL '24 hours'

and

SELECT * FROM foo WHERE created >= NOW() - INTERVAL '24 hours'

First returns the 12 rows I expect where the 'created' field is 2012-02-15,
second returns only one.

Thank you.

--
Wells Oliver
wellsoliver@gmail.com