I mapped my frets to:
1 - A
2 - S
3 - D
4 - F
5 - Space
Hit_1 : 1 ( on num lock panel)
Hit_2 : 2 ( on num lock panel)
And when i'm trying to hit any key + 'F' it didn't work, i.e 'A' + 'S' + Hit_1 works fine and 'A' + ' F' + Hit_1 didn't, and single 'F' + Hit_1 works fine.
If change Hit_1 or Hit_2 to any key that not on the num lock panel it works fine.
Important: I'v read FAQ, and my keyboard is alright cause in other games (i.e. Flight simulators and Fightings) this combos works.
ps: sorry for my awful language
