403 forbidden error

[DocBenny]

I've got this problem started on my forum that it's affecting all users.

Whenever you click a link to a thread, mostly directly from the main forum page(so whatever is the latest active thread) this error message displays.

Additionally then it starts to come up continuously for whatever link is clicked and some avatars and other forum images don't display, until you close the browser and open up the site again.

Error message:

Forbidden
You don't have permission to access /forum/index.php on this server.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

In the vb.com forum there was a thread about this problem, that suggested that we create an .htaccess file in the main forum directory with the code:

<IfModule mod_security.c>
    SecFilterEngine Off
    SecFilterScanPOST Off
</IfModule>

But when I did that, the problem still persistet.

Does anyone know if there should be something more to the code, or something else done.

Any help would be appreciated. Thank you in advance.