I've installed a personal firewall and can't access the site any more.
A
You need to configure your firewall software so that it allows the PCG website to set and receive cookies. The following screenshot shows where to set this option in McAfee's software.
Q
I get warnings about the 'The host you are trying to send the input from is not a valid host' when trying to post to the forums.
A
You need to configure your firewall to allow HTTP_REFERER ("Referrer") information through for the PCG website.
