Spotify released a pretty major update a little while ago. While they introduced all kinds of interesting new features, they also broke some old ones, like support for remote controlling the desktop client using 'AppleScript'.
Denied uses AppleScript to retrieve information from Spotify and tell it to skip to the next song. Needless to say without AppleScript Denied is pretty bad at saving your ears in Spotify. Note that Rdio and iTunes are unaffected by the way.
Luckily the bug is pretty simple to solve and Spotify has said they're planning to release a definitive fix pretty soon. Until then, you can use this little patch I wrote that will re-enable AppleScript with the click of a button. Super simple.
So, if you're experiencing any trouble using Denied with Spotify, download the patch and start saving your ears from crappy music again!