When trying to use the theme editor, it says
If this file was writable you could edit it.
at the bottom of the screen.
So I use my ftp client to go and change the permissions of the theme directory to 666, as suggested in another post here. As soon as I do that, I start having all kinds of major permissions problems and WP starts acting wacky, the site cannot be updated, new posts do not show up etc.
What's going on here?