The new version of MATH CAPTCHA (adapted from 1.7) for version 1.6 DOES NOT work. The checkMathCaptcha() function is defined but is NOT USED anywhere in the code.
We need to change lines 322, 639 and 859 (relative to latest 1.6 download version):
Replace mathCaptcha($_POST['calc'], $_POST['sum'])
with checkMathCaptcha($_POST['calc'], $_POST['sum'])
In addition, we need to change the function definition at line 1977:
function checkMathCaptcha($inSum = '', $inCalc = '') {
should become:
function checkMathCaptcha($inCalc = '', $inSum = '') {
Hope this helps...
Please let me know if I'm wrong.