Maybe some silly questions but paint me silly:
1. How did you get copies of the work computer files onto
your home PC? Did you "http" publish them from the server
to your PC. I would guess no but you should have.
2. Are you using the EXACT same steps to publish from
your home computer as you did from your work computer (it
could be as simple as typo errors)? Did you use "http" to
publish from both computers? If you used FTP at work and
http at home, your server may not have working Front Page
Extensions which are required to use http publishing.
Hence, the error message you are receiving.
3. Can you open the site "live" using Front Page on your
home computer? If not, an indication that you are not
doing the same thing at home as you do at work.
4. What is your firewall situation at work and at home?
Firewall settings can affect your ability to publish.
By the way, once you resolve this issue, do you plan to
continue to update your website from both computers? In
doing this you stand the risk of overwriting work done on
one computer with work done on the other.
To avoid this you should publish from the server based
web to your disk based web on the computer on which you
will be making changes prior to making any changes to
your disk based web. Once changes have been made, publish
from the disk based web to the server based web.