I often use my Spotify Premium account on my work computer running Win 8.1 latestes update etc. Spotify version 0.9.8.... (why don't you take the step and make a version 1??)
Today I have at least 4 times experinced that the playlist I was listning to was being replaced by something completly different. The playlist is still visible but it's not music from the playlist that's played.
I also two times today experienced that while on pause Spotify suddenly decided to start playing without me touching the playbutton. The one time I was not even in front of my computer.
(I don't believe in God or Ghost, so I think we should look for the problem in your code)