Random permission problems

If when you are posting, or clicking from link to link on the forum, you suddenly find yourself at a vBulletin error page saying you don't have permission, (like the image shown below), it most likely is because you are not staying login properly.

With every click, your credentials pass along with your request to the server here. Those credentials are stored in the cookie for wilderssecurity.com. Anything that interferes with the passing of the values stored in that cookie, (whether that be the browser itself, plug-ins, proxy software or servers, web filtering and privacy packages, firewalls, and so on), can cause this type of problem. You'll need to ensure you are passing those values through your entire configuration, all the software on your PC, and the servers at your ISP.

It may be difficult to tracked down, but it most likely has to do with trust levels and filtering being done some where between your browser and the webserver here.