It doesn't happen immediately but sometimes, after 30 minutes or so. Maybe more.
My current setup looks like this:
Audio through RCA -> VP30 -> Audio out through toslink --> Reciever/amplifier.
I haven't tested if the problem occurs over HDMI but my receiver is old and my TV often doesn't like the HDMI audio output from the VP30, giving an error message.
Have anyone else experienced this?