This has probably been already covered, but just in case it hasn't, it may prove to be of interest.  I started noticing that some poses for V4 loaded at normal speed, while others loaded much slower.  This oddity seemed more pronounced in Poser 6 but occured in Poser 7 also.  I checked the Pz2's and compared them.  The slower loading poses contained a HUGE amount of magnet data, and the faster loading poses did not.  So I started deleting all of the magnet info and the poses loaded faster and seemed to work just fine.  But then I wondered if this was a mistake, and that there was actually a reason or purpose for having this info in the file.   Anyone have any ideas?

It's possible that V4's built-in magnets may have been tweaked, but it without analysing the files there's no way to be sure that the inclusion of the magnet data isn't an unintenional.
Personally I suspect it's not needed as the magnets are there to replace JCMs and should respond correctly to the new pose.

Sorry about being so late in replying.  Thank-you nruddock.