Stopping PSE6 from overwritting a file upon OPEN

My workflow is to always leave original files unedited but Elements Editor
always overwrites the file when you OPEN it (so even when I save as - the
originally has been changed thanks to PSE6 Editor).
I noticed when opening files in Elements 6.0 Full Edit - then closing the file
without saving - Elements actually modifies the Exif data on the file and adds
"Photoshop Elements 6.0" as the file creator Exif value. I want the
originals to stay originals (I ALWAYS save under a different name when editing).
Since it modifies the file without save - i wonder what else it might be
changing. This seems like inappropriate behavior.

I haven't seen this behavior with Elements 6.  On my system the file mod

      It only happens when I am viewing the file in Organizer and then move
      the file into the Editor using "Full Edit". At this step the
file is modified
      (Modify date changes and Exif Data changes).