I run a private server for some friends and since I updated it to 1.04 the server doesn't spawn any zombies. The only place i've seen a zombie since the patch was applied is at a heli crash site.
The server is 100% vanilla, no mods at all (and it never had any mods)
I've logged in with different accounts and restarted the server a few times without any change.
(And no, i didn't wipe the server data after applying the patch. I would like to avoid it as far as I can since we would lose all the progress)