FLV Doesn't have sound

I have a .mpg file which plays just fine, audio and all.

When I convert this particular file to an FLV however, all the sound is gone. I have tried using QuickTime convertor, as well as the built-in Flash convertor. Both ways, the audio is nowhere to be found.

I am able to convert other files just fine, just something about this file that Flash doesn't like I guess. Any advice?

Thanks

Anyone? I could really use some help here, I need this video working pronto.... Any help would be very much appreciated.