Audio break up

I also have had an intermitent problem with audio from the SMP breaking up.  I decode the digital audio signal on the HDMI output in a surround sound reciever and it usually works fine, but occasionally the audio is so distorted that it’s unlistenable.  It seems like the signal is too faint and it needs too much gain from the amplifier in the reciever.  This starts as soon as a program is begun, but I always leave it powered on but idle between uses.  When this happens I power off the SMP and restart it to fix the problem (for a couple of weeks.)