I have been playing with hydra for a while (not the gui) and after a lot of trial and error.. used Wireshark to show where the login box was pointing to.
In my case it was pointing to index.asp
(with a failed login you can also simply see that in the browser)
So code for me (with using logins and passes on a USB drive, sdb1) was ;
Am interested to hear any progress your side !hydra 192.168.1.1 -L /mnt/sdb1/login.txt -P /mnt/sdb1/password.txt -V -f -e ns http-get /index.asp