ZUNE HELP NEEDED! Why won’t the folder with my videos I add under ‘monitoredfolders’ show up in my collection?

I use to have no problem adding folders to my Zune collection and then putting the content from the folders onto my Zune, but now I can’t get any videos onto my Zune!!! I don’t know what to do. Under ‘collection’>'videos’ it says “you have no videos in your collection” but I do have a monitored folder with videos added to my collection, but it won’t show up… I know I have the videos are in the right format… and I don’t know what’s wrong. How can I add folders to my collection again??? What’s wrong????

THANKS A BUNCH TO EVERYONE THAT ANSWERS!
MY ZUNE IS UP TO DATE. IF I UNINSTALL IT, WILL I LOSE ALL MY MUSIC/VIDEOS AND SUCH IN MY COLLECTION???