I've just spent a couple of hours trying to get this working, so I thought I'd pass on the knowledge to save anyone else the frustration. You'll have to edit the htaccess file that comes with indexhibit.
Replace the contents with this:
Options +FollowSymlinks
RewriteEngine on
RewriteBase /
RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^(.+) - [PT,L]
RewriteRule ^(.+) index.php
and follow the rest of the instructions that Vaska gives you. This works perfectly for me.