No sound anymore, fedora 15

[Carine Simon]

Hi,

Since recently, I was using Amarok regularly and with pleasure but now, 
the sound does not work any more. I am on Fedora 15 64 bits, kernel 
2.6.42.7, and Amarok 1.4.1.
I have had a related problem last month but the other way around, i.e. 
the sound did work on Amarok but not on Firefox. To fix it, on firefox, 
I have desactived DivX and it solved the problem.
Any idea how to fix this one?
Cheers.