God dag Robert,
I would examine two things (although I'm a og noob, too:
first check the ToolController.class.php for any emoty lines:
#1 ERROR: Error: Cannot modify header information - headers already sent by (output started at /home/www/firedog.dk/application/controllers/ToolController.class.php:326) in '/home/www/firedog.dk/application/layouts/html.php' on line 1 (error code: 2)
than take a look at the functions.php (or maybe config) where the three indices are defined or called:
#1 ERROR: Error: Undefined index: da_dk in '/home/www/firedog.dk/application/functions.php' on line 581 (error code:

#2 ERROR: Error: Undefined index: jp_ja in '/home/www/firedog.dk/application/functions.php' on line 581 (error code:

#3 ERROR: Error: Undefined index: kr_ko in '/home/www/firedog.dk/application/functions.php' on line 581 (error code:

good luck!
rolf