Index: captcha.module
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/captcha/captcha.module,v
retrieving revision 1.25.2.2
diff -u -r1.25.2.2 captcha.module
--- captcha.module	30 Jan 2007 20:17:10 -0000	1.25.2.2
+++ captcha.module	8 Feb 2007 22:26:15 -0000
@@ -103,6 +103,10 @@
 * On submit, captcha is reset
 */
 function captcha_submit() {
+  _captcha_reset();
+}
+
+function _captcha_reset() {
   if($_SESSION['captcha_correct']) {
     unset($_SESSION['captcha_correct']);
     unset($_SESSION['captcha']);    
@@ -111,6 +115,10 @@
 
 
 function _captcha_validate($captcha_response) {
+  if (empty($captcha_response) && empty($_SESSION['captcha_correct'])) {
+    _captcha_reset();
+    return false;
+  }
 
   if ($_SESSION['captcha_correct']) return TRUE;
   if (is_array($captcha_response)) $captcha_response = $captcha_response['#value'];
@@ -122,7 +130,7 @@
   if (module_hook($captcha_type, 'captchavalidate')) {
     call_user_func_array($captcha_type.'_captchavalidate', array(&$captcha_response, &$_SESSION['captcha_correct']));
   }
-  
+
   return $_SESSION['captcha_correct'];
 }