Why doesn;t this Displayport to HDMI Adapter work?

[KWarp]

I bought a brand new 2010 Macbook Pro i7.

I bought this cable:
http://www.amazon.com/DisplayPort-Adapter-female-Cable-Apple/dp/B0025V2VO0/ref=pd_ecc_rvi_cart_1

When I connect my MBP to HDMI to the HDTV, I expect to have another output option for Sound in System Preference. Unfortunately, the option is not there. Display works fine, but audio does not route to the TV at all. (I tried this on 2 Sharp HDTVs and also a Panasonic one. No good.)

What is most confusing is that it has all the correct specs to be HDMI audio compliant, and also the Amazon purchase comments are mixed. Some say audio completely works, others say not at all.

Has anyone here bought this particular cable and gotten audio working?
Do I need to install special drivers of some kind?

 

[brand]

This device is most likely a HDMI 1.2 cable.

 

[phillyphill]

i have the same exact adapter but i've only used it just for picture haven't tried any audio. ill try when i get home within the next hour.

 

[phillyphill]

yeah my audio works fine, i used vlc player and had to change a setting for the audio to work maybe you need to change a setting the program that youre using. cuz im sure it works but who knows.

 

[elpmas]

is the product worth it? also, do u think the vga adapter worth it too?

**3rd party ones, not the one from apple.