Sorry for missing up your post. It didn't show up at the right time in my feed reader that watches the wordpress.org forums.
In order to reference a youtube.com video, you simply add the video tag. Example:
It also supports the legacy syntax of my older plug-in:
but this is a deprecated method, available just for backwards compatibility.
Usually the documentation is available into the admin panel, but for some reason, it doesn't work for you. I'll write some backup docs into an external location.
However, in order to debug the "access denied" issue, I need some more info. Usually, if there's a PHP error, it should show up somewhere (in a log file if it's not displayed).