I tried with 0.8 They all play OK in PowerDVD. Same problem in Media Player, this time I let it download a decompressor for track03.ac3. It said it was downloading the Fraunhofer MP3 codec, and when it had finished, the file played as normal. :confused: I'll just try muxing the AC3s anyway (eventually I want 3 OGM's with AC3 sound), and I'll get back to you. I had to open your site in Mozilla BTW I was still getting DVD2SVCD in IE.