CHMOD 0777, но Wordpress, который все еще не в состоянии записать файлы/папки

1. check the apache error log
2. try lsattr, perhaps there are extended attributes in place.
3. check php open_basedir parameter in php.ini
4. check php safe_mode in php.ini (if it's an old php)

UPDATE:

1. do an ls -lLd public_html/ (or your DocumentRoot, e.g. /var/www, or whatever)
2. do an lsattr public_html/
3. check apache's owner/group : ps -ef|grep apache or ps -ef|grep http
4. put inside the documentroot a php like x.php and access it with the browser.

x.php contents:

<?php
var_dump(ini_get('open_basedir'));
var_dump(ini_get('safe_mode'));
echo exec('whoami');
?>