I did another Google search for firefox no sound (you can too) and found other links where IE and FF could not play stuff from the Flash player:http://www.devhardware.com/forums/software...-ie-102939.html
Look at the part about 4 speakers if that applies to you.
Another same registry load/fix of the same:http://forums.techguy.org/web-email/559748...ox-2-0-0-a.html
It goes back to that registry thing again...
The registry idea I might try next (but that is just me) of course after exporting my current stuff and it could make sense in that these people had no sound with things like youtube and IE or FF but other sound things seems to work fine. The suggestion is a system wide thing - not specific to one browser so perhaps it would fix the problem with both.
You can also use Device Manager to check your sound drivers against the latest on the manufacturers WWW site - a good check since this would also be a system wide thing effecting all browsers and we would not want to be embarrassed about not checking it later. Do you need help with that?
I'm not jumping ship, but I don't have your problem and there does not seem to be a single magic bullet solution. I can only offer the things I would try and make some sense to me! If I did have this problem, I would be compelled to figure it out.
Are you able to do some Googling of your own and see what you can come up with - maybe the magic bullet?
Edited by joseibarra, 15 July 2009 - 10:10 AM.