I've been corresponding with the applicant. Both captcha (the text one and the image-rotation one) have to be solved before pressing the register button. Using 2 captcha methods just keeps us free from the automated spambot registrations, and the few known spammers (by email or IP or userid) generally get thwarted by being in stopforumspam database, or coming from countries known to have human spam registrants to solve the captchas.
Best regards,
Ken