I had it all set up fine and could view the albums when I set it up. An hour or so later, when I click on the album menus (this shows fine), it takes me to an error page, saying that the directory has no index. It does this for every album.

What have I done wrong somewhere? How do I create indexes for my individual albums?

Please post a link.

http://www.thepiedpainter.co.uk/gallery/index.php

You have the modrewrite option enabled but either your server does not support it or the htaccess file is not correct. Run setup and it will tell you.

Thanks very much! I didn't realise that was checked, that it was such a simple little thing. Sorted now.

It is indeed checked by default as actually every webspace should have this feature by now (IMHO).

Actually, not checked by default at all. Setup does test to see if it works and will not set the option if mod_rewrite fails. However, setup NEVER overrides if the option is already set. The setup log should indicate a failure, though.