It is definititely SonicStage CP ver. 4.3 - I have the CD in front of me. It mentions Vista on the disc. I also tried downloading the newest version from Sony's website and got the same result. The DVD drive is working until I install SonicStage and reboot. Once it's rebooted, the CD drive doesn't work. If I roll back Windows to just before I installed Sonicstage, DVD drive works again. Really bizarre For now I've installed on my XP-running laptop without any problem, so it's not the end of the world.