I had so many problems with wordpress installs that i thought i am sure with this very special script. But the spammers do not sleep. i dont understand why they are doing so, no one will hit such crazy domainnames.
To avoid this maybe it would as well be helpful to have a forbidden words list, as suggested some time ago by some member here.
Or, that links / domainnames only can be added through a special field, which automatically needs to be reviewed, while the answer or comment already is active.
For the moment I activated recaptcha, I had about 15 questions a day without captcha, now i will see how big is the difference. The site is only 2 weeks old.