Reads like your vertices are being modified, either the order, scale or translation at some stage of the process. I don't use Max so of limited help but when using Zbrush I would take the obj geometry straight from the Poser runtime to bypass all the box ticking shannigans. This loads the whole figure but I would be surprised if Max didn't have a way of just exporting a single vertex group once the morph has been created.  There's also a third party script that people use to export Poser objs but the name escapes me for the moment (sounds very good though).