cvs -z9 diff -u -F^function -- captcha.module (in directory C:\devroot\cvs-drupal\contributions\modules\captcha-HEAD\)
Index: captcha.module
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/captcha/captcha.module,v
retrieving revision 1.29
diff -u -F^function -r1.29 captcha.module
--- captcha.module	23 Dec 2006 14:22:09 -0000	1.29
+++ captcha.module	3 Jan 2007 02:27:19 -0000
@@ -181,6 +181,7 @@ function captcha_captchavalidate(&$captc
   }
   else {
     $correct = FALSE;
+    watchdog('captcha', "Captcha failed.  Expected: [$_SESSION[captcha]] Got: [$captcha_word]");
     form_set_error('captcha_response', t('The answer you entered to the math problem is incorrect.'));
   }
 }