Hi skydivedad *shiver*
I don't like heights, so I'll keep both feet on the ground unless I'm fully enclosed in an airplane.
The "Restricted Access" error means you're running something that is not 1.5 native on your site, whether it's an old CB plugin or another plugin, module or component. You can try disabling each until you find the culprit and see if there is an update available. Otherwise, sadly, you'll either have to dump the extension(s) responsible or enable the legacy plugin.
You may be able to get a hint which is causing the problem with Joomla debug on or looking in your server error logs.