rebuild/update fuppes database if files are added/removed from directory

The title says it all. I have a upnp server running fuppes that is connected to my xbox360. In order to see the files on the xbox360 i have to manually update and rebuild the database anytime i add or remove files. I have tried cron jobs to do it every 20 min which works, but if I am streaming content to the xbox360 when the cron job runs the steam is stopped and the database doesn't get rebuilt. I was wondering if there was a script that could determine if files had been added/removed to the directory and then run the cron or the needed commands.