Settings page coming up as WSOD

When I click to go to admin/user/captcha, a blank screen appears instead of the settings page. The message in the log entries is 'require_once(sites/all/modules/captcha/captcha.admin.inc): failed to open stream: No such file or directory in /var/www/vhosts/wetstyle.ca/httpdocs/includes/menu.inc on line 348.' It looks like there was a file called captcha.admin.inc in 2.5 but not in 2.6 and core is still looking for it. We are up to date on core at 6.33 so am I missing something ??