Hi Sheerman!
Sorry to say but the digital audio input on the BV7 isn't what it should be.
The problem is that the BV7 only support AC3 sound format (multi chanel) such as DD 5.1.
When playing 2ch sound as in Apple TV the digital sound format is PCM and that is not supported in by the BV7. The only work around is by pluging in both a Analog 2ch sound and the digital coax. The BV7 the selects the digital sound if availible. (Works like that with STB)
Hopes this answers your questions but mybe it doesn't make you happy...
/Ola