With upgrade to QT 7.1.2 and iTunes 6.0.5(20) on Intel OS X 10.4.7, files are not played.
With upgrade to the abovementioned versions, playback ceased to function. It did work before, so is not a case of "intel not working" per se. In QT Player it says "Error when opening: Movie not found" as I open a ogg audio file. In iTunes, normal view, nothing at all happens. In iTunes with the Remote display, iTunes says that it can't open the file because DRM is blocking me. I made the file myself, so iTunes is lying...
I have 0.1.6, according to the Info popup on the .component file.