I am not a complete noob and have read several posts on the "500 Internal Server Error" on this forum, but I can't seem to get zenphoto working. Whether i use a subdomain or its own domain, whenever I navigate to /<server_path>/zenphoto/zp-core/setup.php I get the following:

The server encountered an internal error or misconfiguration and was unable to complete your request.
...
More information about this error may be available in the server error log.
...
Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

There does not exist a ".htaccess" file in the root; there is a similar file in the /zp-core directory (named htaccess w/o the leading "."). I've copied it to the root and renamed it; no dice. I've changed the permissions of the files and folders to 755 and 777. did not work. I've installed versions 1.2.9, 1.3.1.1, 1.3.1.2, and the latest trunk from 2010-12-12; none have worked.

Any assistance would be appreciated.

i dont mean to keep posting, but the post isnt showing up?

Perhaps a little bit of reading would be of use for you. Particularly the note below the `Reply` box where you typed in your many posts.

In addition to that, maybe you should find out what your server logs are telling you and report that back as well (as you no doubt have seen int the error messages you have posted.)

Since you say there is no htaccess file setup should put out a note about that and offer the option to create one.