Using an iPad on WiFi, I was able to get on the site. Most of the tabs opened, some slower than others, but no gateway error messages or other error messages. I did see two messages from Tim Kidwell in the Forum apologizing for the gateway error problem, but one was in April and the other in August. He did say they were working on the problem, but shoot, that was a month ago.
Try rebooting your device and/or your router/modem, see if that helps.
Mac