Synology DSM 5 produces clicks

After upgrading to Synology DSM 5 I get an annoying click between most of the tracks when playing a whole album. It happens regardless of file format (wav, mp3) and is audible both on the digital and analog out.
It doesn't happen when I use Synolgy's own DS Audio on my iPad. So it must relate to the SBT. I didn't have this problem at all with previous versions of the DSM software.

Any suggestions?