I have been using a Kenwood VR-507 receiver for the last few years. I just started noticing that when I start watching DVDs that there are clicks coming from the receiver. It appears to be occurring when the disc first loads up and when it switches from the Warning screen to the main feature. If I had to make a guess about it, I would say it clicks when it is changing from an analog to digital audio signal.(I have it set to D-Auto) It is the same kind of click that is made when switching between Video 1(VCR), Video 2(Toshiba DVD), Video 3(Xbox), and DVD/6CH(Panasonic DVD). Is this noise normal or is this a sign that my receiver is going bad? Any and all help is greatly appreciated.