Sharing iTunes btwn two users -- getting new music to show up for both

I'm setting up a new PC with Windows 7 and, at the same time, setting up two new iPhones. In trying to keep my wife's iPhone linked to her Apple ID and my iPhone to mine, I followed the directions here -- http://support.apple.com/kb/HT1203 -- and set up iTunes on each of our Windows user accounts and put the iTunes Media Library files in a public location we can both access.

My problem now is, when one of us adds new music to iTunes (to the shared, public folder in Windows), it doesn't automatically show up in the other's iTunes library. I know that I can manually go in and use "Add File/Folder to Library...", but, is there a way to have this happen without user intervention?

Many thanks for any help you can provide!

Bobby