I notice that some of you are seeing your Sony televisions switching to "vivid". That makes me think of these parts out of the manual:
"Control for HDMI" in "System Settings", when connecting a Sony TV that is compatable with BRAVIA Sync the S350 can control certain aspects of the TV's operation.
"Theater" button on the remote, when pressed the player will automatically switch to an optimum video mode for watching movies. When connected to a Theater-mode compatible TV using an HDMI cable, the TV's video mode switches to Theater Mode.
So maybe you guys have Sony TVs and have the S350 set to "Control for HDMI" on, and that's how the player is messing up your TV settings? If that is indeed what's going on, then it's probably for the best to disable the "Control for HDMI" to avoid someone elses predetermined notion of "best for you" to be forced down your throat.