Did something change in a 1.2 hotfix regarding how dates get stored?

Everything is in the Central Time Zone (-5 DST). I create a new opportunity
at 1:30p this afternoon and it's createdon = 5/4/2006 13:30 (expected 18:30
UTC). In a custom date field, a select 5/4/2006 and it gets saved as
5/4/2006 0:00 (expected 5:00 UTC).

I change my user to the Pacific Time Zone (-7 DST) and repeat the test.
createdon = 5/4/2006 13:40 (expected 18:40 UTC) and the custom date field
= 2:00 (expected 7:00).

I have researched this in the past and always saw (I think) these dates
getting saved as UTC. Did I miss something here?