Vista Directsound SPDIF problem

[csy]

I'm hoping someone can help me with configuring Vista/GBPVR Directsound.

This is with reference to GBPVR Playback audio renderer used for Freeview|HD AAC and AC3 audio.

I've got a "Soundblaster Audigy 2 ZS" soundcard with inbult SPDIF DD/DTS hardware decoder that I wish to take advantage of. The problem is Vista does not automatically route the software decoder (AC3 filter) SPDIF output to the Directsound:SPDIF renderer, and instead GBPVR must be explicitly configured to use that audio renderer. However, GBPVR also uses the same specified renderer for the MPEG2/AAC software decoders, hence the decoder PCM output is also sent to the Directsound:SPDIF renderer with consequently no sound output as the hardware decoder does not support PCM.

Vista Sound configuration allows you to define which audio renderer is the global "Default Directsound Device" and ties the master volume control to that renderer, but this does not appear to automatically route decoder SPDIF output to the SPDIF renderer, AND route other decoder PCM output to Speaker renderer.

Ideally, I want GBPVR Playback to use:
AC3 Filter to use DirectSound:SPDIF renderer
MPEG2/AAC decoders to use Directsound:Speakers renderer

Any ideas how I can do this?

In WinXP it just worked!