I've got through to step 0 too, did the main site and captchha load fine and did you fill in the captchha first time? I think I've had a 502 before.

(as a tip for the Internet, my general rule is less than 400 is a you error, 400+ is a server error (around the 500 mark is a script error or access error due to some sort of "dos"/service error ).