Are you using the full url in an include function for this frame?
This is what I use.
<a target="ifr" href="http://xx.xxx.xxx.xxx/Weather_webcam_videos/index.php">Previous Weather Videos</a>
I do get access to the page, and nothing in the server log.
An access denied message means that the server is configured not to allow access to the requested url, either to all, to specific addresses. or to all but specific addresses. There are only two places that can be done, the Apache conf file and htaccess.
Check the server log. My guess is there will be a message something like:
date/time [error] [client xxx.xxx.xxx.xxx] client denied by server configuration: requested url