My songs and playlists don't play - but the crappy ones on the Spotify home page do

[OrionSafari]

I have a Spotify Premium account. On my laptop I created a singl playlist of some 230 songs. I went to my car radion (Insane Jeep Audio JK1001) and downloaded the Spotify app and logged on. I made sure the storage settings were to SD card and I downloaded the entire playlist. I have nifty green icons next to every song in the play list. But I can't play them. If I click Shuffle Play, nothing happens. If I click the song, nothing happens. Online or offline - same thing. But if I go to the Spotify homepage and click one of the generic crappy playlists featured there, those songs play. I can take a single song of mine and make it play 'next'. That's the only way I can play my songs. It's darn inconvenient though. I want to just have my single driving playlist, be able to click shuffle, and be done with it. The goal is to do this offline, but if I can't even do it online, what is the problem?