Topic: INFO: Bad HTTP_REFERER
If you get an error stating that you were referred to a page from an unauthorized source the problem is most certainly one of the following:
1. 'Base URL' in Admin/Options is not correctly set.
2. You are not visiting the forum by navigating to the URL entered in 'Base URL'. You must visit the forum by entering the 'Base URL' in the address bar of your browser. If 'Base URL' is http://a.b.c, you must enter that in the address bar (not http://localhost or http://192.168.0.15).
3. You are browsing the forum through a proxy or firewall of some sort that is stripping HTTP_REFERER from all requests. Norton Personal Firewall and Kerio Personal Firewall 4 are the only ones I know of so far that strip HTTP_REFERER by default. Popup/ad stoppers are also known to do this in some cases (most of them don't though). See this post for info on how to setup Norton to circumvent the problem with Norton.
The error should only occur for moderators and administrators. The reason for the error is that PunBB, upon receiving form data, checks from where the data was submitted and if that page doesn't match 'Base URL' + the name of the correct script, it won't allow it. The check is there for a very good reason, trust me :-)