The cause of the distortion in these situations is the 'propagatingScale' channels, Poser primitives use 'propagatingScale' channels which means that if you scale a parent prop its chilldren will automaticly scale with it, but when the parent prop is scaled the direction of the scaling will remain relitive to the parent, not the child. When you export then re-import a Poser primitive Poser adds 'scale' channels, not 'propagatingScale' channels, so you don't get the distortions when you rotate the child. Of course it has to be the parent prop that is exported and re-imported, just doing it with the child will have no effect. An alternative to exporting then re-importing an object would be to open the pp2 (I asume it's a pp2) in a text editor and change the channel types from 'propagatingScale' to 'scale'. However after doing this you would need to re-scale the child prop, you would probably need to reposition it too. To get the pivot point "hinge" or more correctly in Poser speak 'Origin' in the right place, from the menu bar do; Object > Properties > Display Origin, this un-hides the OffsetA (Origin) channels in the paramiters pallet. It's best to set the origin before translating or scaling the prop, othewise moving the origin may move the prop.