Just a note for people on Mediatemple (grid server) trying to install Zenphoto, you have to edit some extra things in the zp-config file. I spent a while figuring that out, so perhaps this message will come in handy for people with the same problem.
In zp-config, at line 139 and 140, there are two Path overrides:
define('WEBPATH', '/zenphoto');
define('SERVERPATH', '/home/####/domains/domainname.com/html/zenphoto');
(where zenphoto is the directory where zenphoto resides in, #### is your website number , and domainname.com is your domainname).
Also at line 24 the $conf['mysql_host'] needs to be edited, since Mediatemple upgraded you have to connect to SQL with (in my case): "internal-db.s####.gridserver.com" (with again the website number).
