I'm confused as to what you are attempting to do.
As a premium member, you are not under a moderation restriction, since we know who you are. So, if you are attempting to PM another member, you should be able to do so. The part I don't understand is the "permission to access" message you are getting. If you would explain exactly what you do to get that, we might be able to straighten out the problem.
When I try to "Send a private message" or "Send Email Message" with the link to the right of the broadcaster's description page here on radioreference.com (the page has three tabs on top, "account" "bio" and "shack" and contains a profile picture, general information, and "badges" to give you a description of his page), I get the following message page...
"vBulletin Message
andersni, you do not have permission to access this page. This could be due to one of several reasons:
Your user account may not have sufficient privileges to access this page. Are you trying to edit someone else's post, access administrative features or some other privileged system?
If you are trying to post, the administrator may have disabled your account, or it may be awaiting activation."
It is as if it thinks I am not a member or am trying to edit the other person's page, which I am not trying to do, only message.