Weird things with track changes

Word doc originally created in XP. Has been passed around
to several people with track changes active. The last
person to edit the file accepted the changes. That last
person is not me. When I print the document I can view it
and print it without track changes. Several people can
print it and view it and no track changes show up. I
opened the file in Xp and Word 2000 and when I
toggled "track changes" on and off nothing happened to
the doc. That is the way it is supposed to happen right???
However, this file was sent to several other people (not
sure which version of Word they are running) and when
they open the file the track changes are there
automatically. Any ideas? Thanks in advance.