Apple TV2 Sound problem with LG PLasma TV model42PG60UD

Hi

I Purchased an Apple TV2 last week and have been unable to get sound on my LG PLasma TV Model # 42PG60UD and need help. There is sometimes a little static noise. The actions I have taken so far to resolve are

• Tried Apple TV in 4 different HDMI slots on TV
• Confirmed cable I was using was OK by testing with DVD Player, DVD recorder, X Box, WII. Sound and picture OK on all
• Tried 2 other HDMI cables with same results as above
• Unplugged everything so only Apple TV was plugged in to television.
• Altered audio settings in Apple TV and television as per other discussions on this subject. Dolby on/off/auto. 16 Bit. Dolby or PCM on television.
• Confirmed Apple TV2 OK by testing on another television.
• Tried using optical digital cable from Apple TV to television.
• Apple tech called me to run through and could not solve and suggested i return the unit.

The unit works well. Can play video, view youtube, watch trailers, watch photo slideshows from Itunes etc just cannot hear anything.

Any comments appreciated on settings, configuration etc

Regards