For Joomal 1.5 with CB just this in your cb.fireboard.php file which is located in:
{your joomla}componentscom_comprofilerpluginuserplug_cbfireboardplugin
Under defined( '_VALID_MOS' ) or die( 'Direct Access to this location is not allowed.' );
paste this code:
DEFINE('_UE_USER_FAVS', 'Deine Favoriten'

;
DEFINE('_UE_THREAD_UNFAV', 'Kein Favorit mehr'

;
DEFINE('_UE_USER_NOFAV', 'Keine Favoriten'

;
DEFINE('_UE_USER_UNFAV_ALL', 'Zu den Forum Optionen wechseln'

;
DEFINE('_UE_fb_CONFIRMUNFAVEALL', 'Wollen Sie zu den Forum Optionen wechseln?'

;
And it will show up the right names on the cb fireboard tab. I named _UE_USER_UNFAV_ALL like I named it because when I activate the checkbox for _UE_USER_UNFAV_ALL a message appears which is _UE_fb_CONFIRMUNFAVEALL so I named it what it does on my setup, after clicking okay it redirects me to the users fireboard profile.
Hope this helped and check what _UE_USER_UNFAV_ALL is doing on your system with _UE_fb_CONFIRMUNFAVEALL.