[X4U] sound w/ embedded Youtube videos

[Kabookie]

On a MacBook Pro w/ 10.4.9 and all updates, when viewing any web page  
with an embedded Youtube video, I get no sound. If I click the video,  
taking me to the original YouTube web page, it plays fine.

I checked my Flash settings and there really doesn't seem to be  
anything controlling sound.

Does anyone else have this issue or know the problem?

Thanks -
Kai