Movieclip halts before looping

I have a seriouse problem and its buggin the hell out of me.
The problem is this, im trying to sync vibrations in the background with sertain points in the background music, if i use “loop” in the sound settings for the music it will eventually loose sync with the vibrations, so i use “start” instead of “loop” in the sound settings but then i get a gap between the loops as if flash needs time to go back to frame one. Does anybody know how to fix this?
All i want is for the music and the vibrations to be in sync.