Shared Folders - new files in subfolder not visible

I am sharing a folder of photographs on my Vista box with 2 other XP Pro
machines on my home network. Everything works fine (including printer share
both ways) but I have what I hope is a simple question I cannot find an
answer to.

When I add new files to a sub-folder of my "My Pictures" folder, those files
are not visible on the network until I re-share the folder, which takes some
time as Vista has to apply permissions to thousands of files located under
"My Pictures".

Is there a setting that can force new files to have the same sharing
permissions as the parent directory??

Please advise!

Thanks,
CR