Dolby Digital problems on BDV-E870

[abcatch]

I have a KDL-46NX703 with a BDV-E870 and SkyHD box

The problem is that I can't automatically switch the audio input to the BDV between the Dolby Digital Optical input (Sky) for and the TV HMDI input.

By configuraing the BDV-E870 set-up I can switch the HMDI Audio Return channel to "OFF" or "AUTO"

• In "OFF" mode the BDV uses the Optical input from Sky and I get the Dolby Digital (DD) output (5.1 speakers)
  
• In "AUTO"  mode the BDV uses the TV HDMI signal from the TV and I only get a PCM stereo output (2.1 speakers) and I can't then get Dolby Digital.
  

The problem in "OFF" is that I can't override the Optical (DD) input if I want to use the TV features such as Internet content and stream music. The Optical is used and I only get the Sky audio channel.

There should be a way for the BDV to either automatically or manually switch between (i) the Optical input or (ii) the HDMI (TV) channel.

Does anyone elase have a similair problem?