I just installed zenphoto version 1.2.6 [4654] current nightly.
There seems to be some problem with the contact plugin. It does not send the emails even if it says so. As well email field seems to be always needed even if marked to be hidden or not necessary. Email is not sent ether to the email given if the field is avalible.
as well the admin tabs are all over the place, and layout all over the admin goes all over the place. See screenshot.
http://img.skitch.com/20091106-xnrg4hj5g4xdw341ur8ymnpser.jpg
I figured as much that you where playing with the tabs...
I will update tomorrow and see if it works. The error with having to give email address is like this. Here I only have Subject and Message for example, and it asks for email address even though the field is not available.
Screenshot.
http://img.skitch.com/20091106-j6prkcd62eu6w2yk148wcf5yap.jpg
Just a note: the nightly builds have two mailers included. Whichever one you are currently using, you could try using the other. I think the two are named "zenphoto_sendmail" and "PHPMailer".
After trial and error I am not able to get the contact form going, I have one problem with it, it does only send the email to the one given in Admin it does not send the email the user gave as his own email in the contact form. I guess it has something to do with the hosting plan I am installing this on. As the email the user gives is an external one.