Ask the author(s) which software they are using. If they are not using Word, their software might not be able to track changes and might not be able to properly keep that information.
I, for example, haven't used Word for quite some time. I have OpenOffice on my Mac and I can open Word files with no problem (I can also save in Word format), but I'm pretty sure that the differences between the software wouldn't allow total compatibility, especially with these more sophisticated functions.
malu
