Vista Shared Folder Files not Updating

Hello all, thanks for your help.

Goal :
Sharing a Vista 64 Home Premium Folder with an XP Laptop.

Problem :
XP can view folders, but not files, in the Vista Shared Folder. Files that were in the folder when sharing was setup in Vista are accessible, but new files are not displayed. New Folders do display, however.

System Setup :
MSHOME network, Vista private network sharing of a single directory. Vista connected by cable, XP laptop by Wireless.

Already Done :
- Triple-Checked Permissions (guest, everyone, etc.)
- Normal Vista Sharing configuration in place
- Checked through specific settings for 'guest' and 'everyone' access of the folder, including 'read files..'
- Checked the net in detail..no luck

The folder I'm sharing is a P2P download folder. Sharing doesn't work properly when the program is on or off, so it doesn't seem to affect anything.

Other things I've done :
- Turned 'indexing' on
- Made sure 'read only' was not enabled under folder settings.

Thoughts?

Thanks,
acijanos

Update :

The P2P stuff isn't a factor - created a new directory and shared - same problem.

I'm wondering if it may have something to do with XP. (service pack 3)