I've got the case sensitive to work. The code above references a post rather than session following this text :
"Next let's try removing and then adding back but as case sensitive:"
Spent the last couple hours testing and caught the wrong binding on the initial selection.
The main issue was the initial bad code that had issues with it's parentheses:
$WAFV_Errors .= WAValidateLE(((isset($_POST["Security_Code_1"]))?$_POST["Security_Code_1"]):"" . "",((isset($_SESSION["captcha_Security_Code_1"]))?$_SESSION["captcha_Security_Code_1"]):"" . "",true,35);
But I can not recreate this condition so will have to dismiss the case and watch for it next time.
Thanks for your help.