No sound with Atv, connection DVI and soundcable

I have my Atv connected with my Philips HDready TV:

Atv with HDMI cable to DVI in the TV and Atv optical sound cable to stereo jack (3,5) in the TV.

Perfect pictures/movies, streaming from the iPad, iMac and iPhone works fine......but NO SOUND.

Help what can I do so solve this...

Already started up again, pulled out the cables and still no sound.

Also the Dolby set off in Atv..still no sound...

If this can't be solved it is a crap investment.. :-(