Problem with receiver, or ps3, or i dunno...

[Lt. Aldo Raine]

I have a problem, and im not sure where its coming from, when i watch blu rays i notice that i hear crackling sounds, i noticed it alot in leon, and have notice it other movies too, well alot of movies, but no issues when playing games or blasting my music of my ps3
i have a ps3 slim, hooked up to a sony str dg720 by hdmi
i have tried to bitstream the audio instead of lpcm, to see if there was a difference, and there wasnt
i tried switching around hdmi cables and receiver slots to see if there was a difference, but there wasnt
but then i hook up a digital optical cable from my ps3 to receiver and sent the audio through that, the problem went away?....
what do u think the problem lies with? ps3 or receiver?
im hoping its my receiver because im planning on getting a new one anyway
i just got my ps3, i would exchange it, but ive had it over the exchange time
same with receiver
any thoughts?
any questions feel free to ask
thanx