julien on "when I logout I can't login again"

I have just installed zenphoto 1.4.5.7
Did the setup and created admin user
Logged out...
Now I have the "Gallery page" but I can't see anywhere a login link or even the admin tab. I am just stuck on this page "Gallery" I can't do anything.
Can someone help me please. I am just a simple user who wants to use the standard package without putting my hands in the code.
Thanks