Dreamhost + PHP 4 + Zenphoto = "No input file specified" error.
At first, I used the work-around mentioned here: http://www.zenphoto.org/support/topic.php?id=3503#post-21005. Editing the .htaccess file and changing the "RewriteEngine" to "Off", I was able to run the setup.php file. However, the paths weren't setup correctly, so 404 errors were rampant. Just before giving up, I thought I'd check the PHP version I was using. Switched it from v.4.4.8 to v5.x, re-uploaded the .htaccess file with RewriteEngine set to On, re-ran the setup.php file once more, and boom! Works perfectly.