The custom index page allows you to have a "size" gallery with an introductory index.php page.
In the case of the Effervescence+ theme, there is a script gallery.php which is what would normally be the index.php code on a non-zenpage installation. When zenpage is enabled and the custom index page option is set to gallery.php The initial page you view in Efferevescence+ is the news page. There you will find a sidebar link to the gallery which loads gallery.php and shows you a normal zenphoto gallery.
The Zenpage is working great so far - thanks acrylian!!!
I do have one issue, when clicking on an image I'm not getting the image to pop-up. I just get a black transparent screen and it gets stuck.
Any ideas? Go to dallasalicerocks.com/gallery and click on any of the images to see the issue. Thanks.