All of this is based on my knowledge of dolby TrueHD being lossless (dial norm on HD-DVD aside) and used to conserve space and bandwidth other than using the bulky PCM. Why would Spider-man 3 have both? PCM is mainly used for compatibility with players in case TrueHD and DTS Master are not supported. If there is a compatible lossless track on the disc why waste the space on another? is it for the core DD track within the TrueHD? For people who have TrueHD receivers? Then again, if you have the Bandwidth and space, then use it. Any thoughts?