Empty Playlists with iTunes Match

I have subscribed to iTunes Match and enjoy having all the songs on my home computer available on my work computer. However, on my work computer I've discovered that most (not all) of my playlists are empty. A small empty cloud icon appears next to the playlist name. The playlists that do contain songs display the cloud icon with a download arrow on it. How can I get the songs to appear in my empty playlists?