OS: Ubuntu 12.04 LTS 32bit
Gfx: Ati 6970HD
Firefox and Chrome wont play audio correctly through my monitor- HDMI

I can how ever, play audio with VLC through my monitor(HDMI)
I can also play audio through my headphones with chrome and Firefox

The audio works HDMI and headphones, Flash works with only headphones not HDMI
any help would be appreciated

Thanks