I first heard of it in a complaint in Renderotica by someone who put a skinny elf-girl and a big muscular man in the same scene; he had made and saved the two separately. If he called the elf first, the man went skinny when he was called. If he called the man first, the elf looked like a stevedoress when she was called. I later reproduced this fault with the "hero" morphs of two Poser 4 Nude Men in the same scene. By my definition, that sort of malfunction is a bug. I might know where this bug got in. Normally, when one part contains a pointer to another part that might be in another model, the reference is written e.g. thus in my aqualunger model:- actor mouthpiece:2 { ... parent head:1 inkyParent head:1 nonInkyParent inhbtube11:2 and the model is referred to as colon and number (here model :1 is the wetsuitman and model :2 is his aqualung), and Poser updates these numbers correctly. But a slave points to its master in a different new confusing way, e.g. in the Poser 4 Nude Man's left collar:- targetGeom heroLClr { name heroLClr ... valueOpDeltaAdd Figure 1 BODY:2 SuperHero ... and Poser does not think to update the line "Figure 1" in slaved channels throughout the current scene when Figure 1 is renamed, either by the user or automatically to avoid a name clash.