sorry for bringing this up again
after i changed a new cable, the problem went away; however, it happens again. now it's not on and off anymore. it's always blue like that. So i tried narrowing down the source and it's from the receiver. Connecting PS3 or cable TV directly is fine; only when connecting thru the receiever that i get the blue background. And changing the cables doesn't help. They connect thru HDMI btw.
Anybody know what's wrong with the receiver? Would it cost much to fix?