Sony Bravia KDL 52XBR-4

Running three inputs through new Sony receiver (with HDML cords with one output to LCD.) Same problem whether watching Blu-Ray player, HD-DVD player or DirecTV. All video modes are set to factory presets. Picture is fine, but on end title credits there is a change in "white level" . It happens in same spots, color diminishes slightly then comes back to normal white level. Same problem whether watching on STANDARD, CUSTOM or CINEMA. Also on VIVID although I would never watch anything at that setting. Have tried adjusting backlight level and other settings. Same problem. Have also tried running signal direct to TV without going through Sony receiver first. No difference. Is this a voltage issue?