LG LCD 47LC7DF PS3 HDMI Sound Crakling

I have the above TV for about 4 months. Got the a PS3 and hooked it up to using the HDMI port. Picture is awesome, along with the play - but the sound has a crakling sound to it sounds like static or a bad speaker. But the sound is fine any other time DVD & regular cable & HDTV. I am on my 2nd PS3 & HDMI cable. The tech at the store seems to think it the HDMI card in the TV since I have tried all three ports. One more thing I even muted the TV and it even come across my suround system also. I read the manual front to back with no solution. HELP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!