Hi Rick -

Do you mean that the user is selecting a group of numbered paragraphs and
then trying to use Format > Bullets and Numbering to set a start number?

My guess is that there are several different lists and list templates within
the selection (not unlikely with direct list formatting and previous use of
the abominable B&N dialog or toolbar number button) and Word is getting
'confused' and throwing in the towel.

I would treat the document as corrupt and either save out to (unfiltered)
HTML and reopen in Word, or copy and paste all but the last paragraph mark
to a new file, but really the best advice would be to get the user to set up
consistent numbering using styles for reliability. Lots more information on
this in the archives of this group.