I've added my Vista machine to the networks at both home and work.
I've made certain that the Vista machine has Admin permissions.
I've noticed that while I can create new files and folders across the
networks, I cannot modify them: delete, rename, update (save as in Office
2007).
What I've had to do is save (modify/update) locally to a local hard drive
then drag and drop the modified files/folders to the networked drive.

Gateway Tech support initially told me this was an Office 2007 issue but
I've since realized that no matter what application I'm using, I cannot save
a file across the network that I've opened from network hard drives, nor can
I save to network hard drives, files that I've opened from a local drive. I
cannot modify, rename, delete, etc files I've accessed across those networks,
from the Vista machine.
I am able to modify files on the Vista machine from XP machines on the
network, just not the other way around.

Anybody know the fix?
Is there a new option in Vista that I've missed that is prohibiting me from
full access out?