Track Changes Color Same for 2 Editors, Different for the 3rd Edit

Hi Helpfuls,

I'm using Word 2003 on XP. I (and the others involved) have Track Changes
colors set to display By Author.

We're circulating a doc for editing, with Track Changes turned on. All
users have their own names in the User Information field (in the Options
menu), and work from their own workstations. The changes by the first 2
editors display in different colors. When a 3rd editor makes edits, the
changes display in the same color as one of the other editors, but this only
happens on the 3rd editor's workstation; once the doc is emailed to another
user, that 3rd person's changes do take a different color...but then that 4th
person's Track Changes show up the same color as an earlier editor's.

This didn't happen until recently; normally, when an editor modified a doc,
the color of the changes was distinct--and apparent on that person's
monitor--from the other editors', regardless of how many folks had made
previous edits. There haven't been any recent system changes/upgrades, etc.

If you followed this, do you have any idea what the problem is? Thanks...