I couldn't find a place to report bugs, so my apologies if this is the incorrect location to do so. If you have a song on your playlist twice, an infinite loop is created.
0. Clear playlist
1. Browse to an album
2. Play a single track from that album (track 2, for example)
3. While that is playing now add the entire album
4. When the playback gets to the "other" copy of the original song that you were playing subsonic loops back to the first version and starts playing from that point again.
5. It will continuously do this.