Can't "Get Info" on my iPhone 3G?

When I right-click a song on my iTunes, only two (as opposed to the many more before): "Play (song title)" and "Get Info." When I choose Get Info, and go to the "info" tab, everything's grayed out. NO, the songs are NOT on "read-only." Read-only is UNCHECKED, so that's not the problem. Please help.