I can hear sound some times, but not when flash is running the content. When I click on the volume icon in the windows taskbar, then click mixer, I see sliders for speakers, system sounds, and firefox. But it seems that there should also be a slider for Adobe Flash. How can I get flash added to the sound system?

It used to work until I tried to play Words with Friends on facebook. I made sure that my version of Firefox and Flash are updated.