Beaty and I are testing this now…
It seems that the Vox player is making some changes to the Sound preferences (in system Settings) for OSX. You will notice that while DPS is running, the output device is set to DPSReflector. If you change the output device to Internal Speakers in the Sound preferences window, the DPS icon will go black because it is no longer receiving audio to process.
We noticed that the output device changed from DPSReflector to Internal Speakers when the screen woke up. That is why the icon went black. Turning DPS back on switched the Output Device back to DPSReflector for proper operation. This leads me to believe Vox is improperly making changes to the Sound preferences when the screen wakes up. That may have also happened when you quit Vox and DPS turned off.
My question now is why are we having the issue now and haven’t seen it before? ko.be, have you been using Vox all along?