This is the exact same reason, I needed the advanced settings, except all my keys randomly trigger forever. I can't change the key repeat on my Harmony remote, so wanted to do it in the settings... So I guess I'll have to wait until the next update, before I can use my Flirc.
Just updated to the most recent version (2.2.1). Now all my advanced settings are greyed out, and can't be changed. Tried to run as admin, tried to disconnect the device, and reconnect, tried restarting windows, tried reinstalling software. None of these things worked. I'm on windows 10.