Year 2028/1928

One of my users, userA sent an attachment using ccMail 6.3 to another userB. UserB received the attachment but the date on the file changed to mm/dd/28. In this particular incedent userB was able to read attachment and re-save it. In another case when userC sent an attachment (*.doc) to userD, it change it again to mm/dd/28. In this case the original file could not be read by ccMail or Word. Bios/date/time checks fine. UserA & userB are WinNT and userC $ userD are running Win95
Any incites?
Thank you.