I looked at your site and in your post you said,
This appears to be a feature of WordPress 2.5 which I haven’t been able to disable yet.
No, you might want to disable the plugin causing it.
WordPress does not have any sort of built in captcha system. You have a plugin or something causing this.
thanks, looks like the culprit was http://crazyeddie.info/dealer/dealer.js in the footer.php file of the GlossyBlue 1.4 theme.
Huh. Well, look at that! It’s a captcha defeating system. It’s not checking if you’re human or not, it’s sending the results back to crazyeddie.info to let the thing bypass the captcha from some other site!
Where did you get your theme from? Because this version of GlossyBlue 1.4 doesn’t have that code in it:
http://www.ndesign-studio.com/resources/wp-themes/glossyblue/
That’s where I downloaded it from last week. Hmm…
Yeah, I just downloaded the theme from the same place Otto and just finished going through it – no Crazy Eddie script in it.