If you write a page, and the .htaccess file isn't writable, WP doesn’t tell you that you actually need to edit the .htaccess file and manually enter a new series of RewriteRules for that page. For example: if you create a page with post-slug as “test�, the .htaccess file will be edited and the following RewriteRules added near the top.
Maybe in the future, it would be nice if it said "We detected that you're using permalinks and your .htaccess file isn't writable, so this is what you need to put in there"...
http://raybdbomb.com/03.09.2005/wordpress-permalinks-and-pages.html