[Guitar Hero - Metallica] Video / Audio sync problem

[perdouille]

Hello !

I'm trying to make GH:Metallica work on my computer, with a wii guitar. The game
is working well, but at different time, the music lag and isn't sync
with the video (So it's unplayable)

It's not everytime, so I can't fix it with the lag fixer on the game...
I'm using LLE, and I have very little video lag in game (It's running at
60 fps, and sometime got FPS drops)

(Tried with GH3 too, same problem)

Thanks, and sorry for my bad english
(My PC spec are on my profile)