Not entirely true, Lyrra.. when the cr2 is modified so that a bodypart is called from an additional external object rather than being part of the figure Resource file, Poser often gets confused when opening the pz3 and searches for the object in the pz3's subdirectories rather than it being relative to Poser's runtime, regardless of whether or not that object file is in the right place. This of course doesn't affect most users though, so it's a minor thing to worry about unless you're into creative cr2 hacking.