It seems that others have similar problems, but I've tried everything in every other thread, so would like to check with anyone else might think.
I'm fairly convinced that this is a mod_rewrite or .htaccess issue, but I'm not sure where I'm going wrong.
I've got the htaccess files correctly installed (and have tried adding RewriteBase to them in various configurations).
I've got mod_rewrite enabled, and uncommented in httpd.conf (and I've got AllowOverrides All in httpd.conf, too).
This is an install on a Mac Server, running Leopard Server.
The install is at http://mycroft.mhc.cuny.edu/omeka . As you'll see, that main page loads fine, but nothing else--no Items page, and most of all no admin page. Just 404 errors for all of them.
The root of the install (since this is a Mac) is at /Library/Webserver/Documents/omeka . If that helps.
Glad to answer any other questions--I'm obviously missing something obvious. Any thoughts?