When you click this link on CAPTCHA Examples page, under Challenge "Image" by module "image_captcha" you will see different answers but the image remain the same for all answers.
Confirmed. Problem is that same CAPTCHA session id is used for all images, instead of a unique one for each.
Culprit is http://drupal.org/node/1024370#comment-4219104 (committed by http://drupal.org/node/1024370#comment-4401002). Reverting this oneliner fixes the problem for me
I reverted the commit mentioned in #1:http://drupalcode.org/project/captcha.git/commit/1161a4d
which fixes this issue
Automatically closed -- issue fixed for 2 weeks with no activity.
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