If the PC is running PowerPoint 2003, then it is probably not you. When
you go to the PC, you should start PowerPoint, go to the Help menu, and
choose Check for Updates. Follow the instructions to install the latest
service packs. When 2003 was first released, it had problems reading
files that weren't created in 2003 (including Mac files and PC files
from eariler versions although not all files all the time). They quickly
fixed this (although many many copies were sold for years after that
without the fix), and the fix is contained in the service pack.
--David