[wp-hackers] any hook before auth_redirect() ?

[Malaiac]

I had a allow_autologin() function which allowed a anonymous visitor
to submit a post with his email, and be registered, logged in and
redirected to post.php page.
The function was working on my development version (2.7 r ~9000)
I updated today r 9353 : the function is not working anymore.
It seems that auth_redirect() acts before init (which I took for the
first hook in wp admin page loading)
Before I had :
site.com/submit , form action = wp-admin/post-new.php > init hook
register a new user and log him in > redirect to edit page
now, I have :
site.com/submit > auth_redirect() >
site.com/wp-login.php?redirect_to=site.com/wp-admin/post.php ... and
there the init hook works

Any modification on this side ?
If not, do you have any idea of a sooner hook than init() ?

Thanks
M