Hi Greg and sorry for late reply – we’re just crazy busy recently.
Generally stopping spam is a complex issue and there are many possible reasons your spam is getting through. But first let’s focus on Math Captcha – one of our users say a simple setup is the most effective one: he suggests addition only with numbers and words. Please try that.
If it doesn’t stop all the spam try to combine MC with another plugin – Antispam Bee for example. Both should work smoothly.
If you still experience spam I’d suggest a general code review of all your theme files and plugins. Why? Because there might be security holes or code errors that arise from bad coding practices and make your site vulnerable to spambots.
