I have connected my HD tivo to projector via HDMI (very nice picture)

Connected the audio via the optical output to my Yamaha amp optical input.

If the program is HD with Dolby all works fine. the AMP says Dolby Digital and decodes it fine.

The problem I am having is that other programs which output in PCM dont work. the sound cuts in and out. the AMP says PCM as the input type but the sound is choppy.

DVD/computer/cd optical outputs in PCM work fine just the HD tivo. does not work.

Audio from the L&R Rca works fine.

any one else see this.

It is a pain seeing the dolby digital works fine.

I would be happy if some how the optical tuned off if not Dolby digital so the amp would not see a signal and fail over to the Analogue L&R sound RCA.

At the moment I have unplugged the optical cable and just using the Analoge but seems a shame to miss out on dolby digital when it is there.

tried changing the audio option to PCM but then choppy sound on all programs.