I observed a user getting a captcha for an edit. The message "Incorrect or missing CAPTCHA" appears after the edit, on top of the edit window, while on bottom the captcha image appears. There is more than a screenful of distance between the error message and where the user has to act. The user was confused.

The captcha image should load next to the error, or the error should link the area where the captcha needs to be entered. Ideally, the captcha would be loaded before form submission, e.g. by identifying that a link was inserted.