I have a div that pops up whenever a link is clicked and within that div is a Contact 7 form with a captcha image (a Really Simple Captcha one). If I turn on WP Super Cache the captcha image stops working as the Super Cache plugin caches the image and doesn't change it whenever that page is refreshed. How do I exclude the caching of this captcha png image? I'd like to not exclude the whole page from caching, but just that image.
Thanks for the help!