White macbook : no sound on HDMI

[PenguinApple]

We have two Macbooks, one 2011 gray Macbook Pro and one white Macbook purchased feb 2010.
We recently bought a Samsung UE32C6000 TV set and connected the MBP with a Mini Display adapter to an HDMI cable to the TV.
The TV worked as a second display of the MBP and the sound played on the TV after I set the audio output to Samsung.
So far so good.

Then I did the same with the white Macbook and the TV w orked as a second 1920x1080 display as well, but I could not set the sound output to the TV, the only option was 'internal speakers'.

Both PCs are updated to OSX 10.6.8 so what is the prblem here ? Hardware failure with sound output to HDMI on the white one ?
The white one does output normally to headphones but not to HDMI.

Any ideas here ?

 

[dukebound85]

iirc sound via display port is relatively new. You may have to route the sound another way on the white one

 

[TEG]

If I recall correctly, the 2009 MacBook doesn't support audio over mDP. It was a new feature in the 2010 MBP, and it usually takes a year or two for those updates to transfer to the regular MBs, considering the mid-2010 update included it.

TEG