I have an Asus laptop with Windows 8 and fn+f5/fn+f6 keys (for brightness) doesn't work. In fact, they work, but they can increase/decrease the brightness only 1 time. I mean - after pressing fn+f5 once, nothing happens if I try to press fn+f5 again, before I press fn+f6. This only happens after logging in. At the login screen and during Windows…