I also noted that Comet 21P/Giacobini-Zinner jumped in position when I downloaded orbital elements for comets.  I looked at the Soft02Cm.txt file which Guide downloads.  I was surprised to see html code in it rather than the list of comet orbital elements I am used to seeing.  This file starts as Soft02Cmt.txt and is available at the Minor Planet Center.  The MPC version is the old format.