It appears that it should work - in theory. WMP will play ATRAC files using the Sony codec if SonicStage is present on the same machine - it just can't see them. So one, clunky, option is to copy all my ATRAC files to another folder and rename them all .mp3, which would allow WMP to add them to its library. Another is to stick them all on a USB drive and copy them across to the PS3, but that's going to have DRM issues. I tried to us HIMDRenderer to convert them to MP3 files (also clunky, given that the PS3 has native ATRAC support. What I really want is for SonicStage to act as a DLNA server, so they can play natively. But expecting two bits of Sony to work together is just hopelessly unrealistic, I guess...