I'm not sure if this has been answered. For some reason I cannot see any of the postings on any subjects. The missing song is there, it just isn't available in the multi-channel mode.
There is a statement somewhere on the package that says that the bonus selection is available in SACD stereo only. You will have to choose stereo on your player to hear that last tune. Danny
The bonus track was recorded and mixed by different folks than the album. When it came time to do the multi-channel, the same person who mixed all of the tracks but the bonus one in stereo mixed the same tracks in 5.1. It would have been better if they had listed it as a "bonus stereo-only" track more prominently on the back cover.
The Al Green DVD-Audio had a similar situation with the last track "Belle". It is only available in stereo as the multi-tracks were either missing or unavailable for a remix. It's a shame, because "Belle" is a track that could really stand for a remix, even in stereo.