Audio Popping on PS3

I hadn't noticed it in the past, but today when I turned on my PS3 I heard some very clear audio popping coming from my speakers.  I tried audio from other sources and they were all fine so it's not my receiver or speakers.

What could be the problem?  It does it on games, MP3s and videos.  This hasn't happened before and I think it would have been pretty hard to miss it.

 I am hooked up with HDMI cables to my TV, then Optical audio cables from my TV to my receiver.  It's so annoying.

HELP! 

try running the optical cables directly from your ps3 to your receiver's audio input. There should be less noise and a clearer signal this way.Tertuel

I'll try it, but the thing that bothers me is that it did't happen when I first hooked everything up.