Admin posts display other user as author

Problem with a new installation of WP 2.3 and themes that display the “author”. There’s the original default “admin” plus 2 other users who’ve been added as admininstrators.

I logged in as admin – it says “Howdy, admin” in the dashboard – and wrote a few “lorem ipsum” posts. Except for the “hello world!” post, all other posts made from the admin user account display as having been written by the first alphabetical user after admin. In the Post Author drop down menu the “admin” user doesn’t appear as a choice – only the other two user’s names appear.

Is this a bug? How do I change author to be the blog administrator?

Thanks!