Alright... I had some time to kick around and I thought I should give Vista another try. So...
I've got Vista Ultimate + X-Fi Platinum + Z5500 and running WinDVD 8 Platinum.
Now the Z5500 has a Dolby Digital decoder/Sound processor built into which I would typically use. However When I go into the WinDVD setup... enabling "Digital (S/PDIF) out to External Processor" is blocked out. I can only choose "Analog Sound Card" in the "Audio Output Configuration" Area.
In the Creative Control panel under "S/PDIF I/O" I have set the "S/PDIF input setting" to "SPDIF Bypass"
Any ideas? I use this exact setup on XP and works GREAT. Is this a Driver issue? I know that SB doesnt support dolby digital but they say on there website I should be able to get dolby digital at the software level.
it does work actually. for awhile my audigy 2 zs had no support for digital passthrough in vista, due to drivers... creative has since corrected it though... as far as why yours isnt working, im not quite sure. do you have the latest drivers?