FLV No sound in quiktime and final cut pro

[TimTim]

Hey, i looked around on this site for answers but nothing that fixes my problem.
I have a bunch of flv files that i need to edit, the video plays but without the sound.
It plays fine on realplayer and adobe player but whenever i open them with quicktime then the video plays but without sound.
Also according to quicktime one clip is around 40seconds long while there small clips of maybe 10/15 seconds.
You only hear sound for like 1 second in the beginning and thats it, same story in preview mode.
Whenever i import them to final cut pro to edit i have the same issue, video plays fine but no sound.
I have perian installed, version 1.2.3 , even tried to downgrade to version 1.2.2 but that also didn't helped.
I have no idea what to do, sorry if it's already answered somewhere, must have missed it.

Thanks