When you open your browser debugger and look at the POST info being sent in the AJAX request, what params are being sent over?
I just encountered a similar issue.
My form was submitting via AJAX, and as not all form values were being passed in the request, it wasn’t sending over all the pieces of the Captcha. If you hop into the Captcha source and go to the cptch_check_custom_form() function, it looks for specific params in $_REQUEST. Assuming this is an ajax form submission, you need to make sure all of those are being passed when you submit the form to wherever it’s being submitted, or it will always return false.
cntctfrm_contact_action, cptch_number, and cptch_result are the params you’re looking to pass.
