How can I handle sound on Flash?

Hi guys, My problem is the wrong sound sync is selected. A stream sound can not play that the frame it occupies. Eg: if a sound is 20 sec long in another animation at 12 fps, the sound will take 240 approx frames to play. And also if the length of the frame occupies only 120 frames the sound will play only for 10 sec. :( Have any idea for fixing this problem?