No ScreenTip for Revisions

[David]

Hi,
When you hover your mouse over revision text (i.e., track
changes turned on) a ScreenTip shows the name of the user,
the date/time and the type of revision.

A friend is working in Word 2000. He can see the revisions
in the document, but no screen tip appears when he hovers
his mouse over the text. Other users in Word 97, 2000 and
2002 have no problem seeing the ScreenTip in the same
document.

Any ideas??

Thanks in advance.
DSK