You are confusing several different issues here.
'Protecting for tracked changes' is a setting that locks the document so
that changes are tracked and the user can't turn it off from the toolbar. It
isn't the same as just having tracked changes set 'on' (so any changes are
marked), nor is it the same as having changes (insertions and deletions)
showing up in the document.
Word 2003 will by default open documents in the 'Final showing mark-up' view
if there are tracked changes in the document (whether or not tracking is
currently on, whether or not document is protected for tracking). If
documents created in earlier versions of Word open like this, then it is
because you were (perhaps inadvertently) tracking changes at some time in
the past, and you have never accepted/rejected those changes. Word 2003 has
a new view default here, but it doesn't turn tracking (or protection) on and
it certainly can't generate revisions that weren't already in the document!
I assume the idea of the new view default was to alert people to the
revisions stored in their document to avoid embarrassment, though from the
posts here it often seems to ensure that Word 2003 recipients see changes
Word 2002 senders had forgotten about without even trying to snoop <g>.
The only way of removing changes in documents is to accept or reject the
changes. But if all you want to do is clean out the revision marking,
without any backtracking of the changes you've made, you just turn off
tracking (if it's still on) and 'Accept all changes' (available on the
dropdown menu beside the Accept Change button) - you don't have to accept
each change individually. You can *view* the document without the changes by
choosing Final without Markup, but that will leave the changes in the file,
and they will be visible on opening.