Not able to change Wordpress site url - users being logged out

Question

A client had a problem that the users was logged out after only minutes of inactivity. And wordpress telling that .htaccess wasn't writable(which it was). I checked the wordpress site url and home url and it turned out that the wordpress site url had www including in the url, while the home url didn't. I tried changing the wordpress site url to include www, but it was set back to not including the www when I reloaded the page.

Answer 1

The solution to the problem was that I had to define the the site url and home url in wp-config.php. After that Wordpress stopped complaining about .htaccess not being writable and users was not logged out.

define('WP_HOME','http://www.mysite.com');
define('WP_SITEURL','http://www.mysite.com'); 

Anyone know why this happened all of a sudden? And why didn't Wordpress let me save the wordpress home url from the admin interface?

Answer 2

Were there any changes made to the Database of the site recently?

The home and site url's are also stored in the wp_options table in the DB and can be manually changed from PHP myadmin if required...