Here's a little addendum: ZB2 doesn't like Jessi's mesh, so it subdivides some faces, causing UVMapper to choke later on. I'm enclosing a Python script which fixed that for me, and actually made the UVMapper steps superfluous. Just rename the attached file to combine.py and run it on the original Poser export and the .obj produced by ZB2, piping the output to a new file that can be imported into Poser. I haven't tested this extensively, so there may be hidden quirks, but so far, it works like a charm. Let me know what you think. Oh, and this must be run from the command line, not from Poser. For instructions, look into the file.
-- I'm not mad at you, just Westphalian.