Does appear to be blocking spam

That’s weird.. the reverse is the case in one of my blog.

I thought it was weird too.

Any sign of improvement?

Testing it out again on the site with a high volume of spam. It seems to work fine on another site of mine.

The first spam comment to come in since I re-activated the plugin got through. I had to manually mark it as spam. It is a very lengthy spam post, but I will paste it here if you think it will help.

I can only think of two possible causes.

1. the bot submitting the spam comments probably found a way to pass the captcha test.

2. If you haven’t cleared your cache files assuming u use a cache plugin like WP super cache or w3 total cache, visitor will still be seeing the old pages/post without the captcha implemented.
I advice you clear your site cache.

Let me know if option 2 fixes the problem.

No site caching that I am aware about. I’ll keep an eye on it.

Still getting a lot of spam comments in the moderation queue. Does or can the extension use the comments marked as spam to auto filter incoming comments?

That won’t be possible.

Maybe the bots submitting the forms are sophisticated.

Note: this has nothing to do with the plugin. What this means is, the bot has a way to circumvents recaptcha which is out of my power.

Thanks for the info Collizo4sky