[Edit: I've dived into the PHP abyss and added the math spam code and reactivated the plugin. Let me know via the contact form if anyone has problems leaving a comment.]
[Edit 2: Well, I can't add the math comment spam code into this theme without major surgery, so I'm likely stuck having to sort through thousands of pounds of spam weekly.]
I had forgotten to either turn off my math comments spam captcha thing and I got several emails this morning saying people could not post comments. That has now been corrected. If I stay with this theme, I’ll add the code into the theme files and reactivate it.
One of the main reasons I have it is that if I don’t, my spam filter queue gets a real workout. At times I’ve gotten over 200 per day and I have to look through all of them carefully to make sure legitimate comments are not mixed in with the junk. With the math comment spam thing, I only see about 5 or 10 in the spam queue per week.