The recent hour of downtime was due to a problem with the forum's anti-DDoS provider x4b.net. They've been consistently having minor problems since the start, and this extended outage really sucks, so I'm going to start shopping around for alternatives. Though apparently it's pretty rare for DDoS protection services to offer GRE tunnels at any even vaguely reasonable price.
Thank you for you clarification, good to know that it wasn't anything serious.