I hope someone can save my sanity and help me with this problem! I have my new HTPC connected to my amp with Coax S/PDIF. Applications such as Windows Media Player are working great, sending the correct multi-channel streams as my amp displays "Dolby Digital" or "DTS" depending on the source. One major problem: PowerDVD outputs NO sound whatsoever when I change the audio settings to "S/PDIF". If I set it to anything else (e.g. "2 Speaker", "6 speaker") I just get stereo sound. My suspicion is a compatibility issue between PowerDVD and my X-Fi Sound Blaster drivers, but I dunno. Here's my system spec: PC: Dell Vostro 200 Slim OS: Vista Ultimate 32-bit SP1 Graphics: ASUS Radeon HD 3450 (Catalyst 8.2) Audio: Sound Blaster X-Fi Xtreme Audio (latest drivers) Display: Sony Bravia KDL-32D3000 Amp: Denon AVR-3802 PowerDVD Ultra: 7.3.3730.0 LG GGW-H20L Blu-Ray/HDDVD Combo Drive I have disabled the onboard Relatek audio, and disabled the High-Def Audio on the graphics card. I've done screengrabs of all relevant settings/info, they are here: http://demon.xssl.net/~admin2/spdif/index.htm I've e-mailed Cyberlink support but they are s-l-o-w, and not helpful. I want to play Blu-Ray and HD-DVD discs, so I really need PowerDVD to work. Any help from you geniuses is really appreciated!!