Problem in the sound

Hi
I have a problem with the sound when I add a video file in and run the program I hear the fluctuation in the sound and then it disappears and the audio program and then hardens do I stop it by kill process

ubuntu 9.10

sony vaio vpccw16fa

What is the problem in your opinion?
I want a solution

Thanks

install libsdl1.2debian-pulseaudio

You install this package> install libsdl1.2debian-pulseaudio
But the same problem fluctuation in the sound
Please help me !!

Did the package fix the problem with the program locking up? If so, and you still have fluctuation in the sound, then please make a render, play the render in another program. You want to determine if the audio problem is only on playback or in the signal processing.

Thanks a lot, it solves my problem of sound :D