Moved WP from example.com/blog to example.com, cannot add pages now

I just moved my WordPress blog from a directory up a folder and I’ve changed my wp-config.php by adding these 2 lines:

define('WP_HOME','http://example.com');

define('WP_SITEURL','http://example.com');

Most things are working fine now, but I’m having trouble creating pages… I can create them without a problem but when I view them it gives me a 404 error. Any help?

EDIT: I should say when I add a page like ‘About’, the URL: www.example.com/about show’s an error page.