Question : PS3 optical link to surround sound - no sound!

I have a:
SONY Bravia TV
SONY PS3
SONY DAV-DZ330 Theatre System

I have just upgraded my SONY Home Theatre System from a DAV-DZ280 so that I have an optical audio option, to be able to play surround sound from the PS3 games.

Connections are:
Sky HD to Optical switch
PS3 to Optical switch
Optical switch to DZ330
HDMI to TV from each of the 3 boxes.

PS3 Audio settings:
Settings > Sound Settings > [Audio Output Settings] > [Optical digital]
Dolby 5.1 plus the two default Linear Channels.

Sky HD works great.
DZ330 DVD playing works great
PS3 no sound!!!

Is there somewhere on the DZ330 that I have to choose to accept the signal from the PS3?
Looking at the fibre cables i can see that there is a signal (red light).
Is there a setting I have missed in either the PS3 or the DZ330?

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Thanks for your time in viewing

Please help me get my new toy working!

Answer : PS3 optical link to surround sound - no sound!

Refer this article same as above but with images:
http://www.msexchange.org/tutorials/MF009.html