I am using the latest Wordpress and I have always had issues with the automatic updater.

For the files in the wordpress directory, i set them to permission 770, and add the webserver user 'www-data' as the group owner. I use lighttpd.

However, the automatic updating plugins or installing plugins does not work.

It works if I chmod 777 the files or if I set the actual owner to the web server as well.

What are the best permission settings for security while still allowing the updating feature to work properly in wordress?

Also, by 'not work' i mean, it will go to the screen that asks me for FTP credentials when I try to update.