I'm actually off to a client site today to look at a similar issue. The Administrator levels can see playlists, but the user levels with content/update access cannot. I'm thinking it may come down to digging through the SQL tables to see if there is a table for said users that has a False value where a True value should be. If I find anything, I'll update this later. According to the client, under the playlist tab they see the message "No Data".