In login.tpl:

Code
<a href="{$config.BASE_URL}/ubbthreads.php?ubb=login&lostpw=1">{$lang.FORGOTTEN}</a>

should be

Code
<a href="{$config.BASE_URL}/ubbthreads.php?ubb=login&lostpw=1">{$lang.FORGOT_PASS}</a>

otherwise the link to the forgotten password form is not shown.

This has been present in previous versions as well, but it only just now occured to me to report it as a bug.