This sounds like an Office 2007 bug that was fixed with the first
service pack for that suite. If so, that means the author (or someone
between the author and you) opened the files in obsolete, unsupported
software. The solution is to take a two-by-four upside the head of the
author and stand over them while they fix the problem on their end.
However, short of that, open the files in Word and replace hyphens with
en dashes, which is what they should have been in the first place, and
then import again.