I get a 403 Forbidden message when trying to post a new topic, but not just me, everyone on my Forum does. The Cmod permission are 0644, but you can't post topics, only replies. Please help.
Try to download a copy of your .htaccess file then delete it from your server and check if you are still getting an error or not.
I still get the error.
Try a CHMod of 666 and let us know how it goes. Sometimes servers have an issue with 644.
It still doesn't work.
Check your error logs. Try chmodding it to 770. The default place for apache2 logs are in /var/log/apache2 (That's on Debian, Google it for your specific distro) if it's CentOS it's most likely /var/log/httpd .