Why I'm wondering is seem to notice every time the the FBI warning comes up, the background is not uniform.

Most often it's a corner (usually upper right) is a lot more brighter (paler blue) than the rest of the frame.

Tried to capture below, (this time the bottom is darker than the top).
http://i67.photobucket.com/albums/h316/das75/fbi.jpg

TV is a Samsung plasma PN58S650 about 10 months old. Source is a Sony BDP-S350.

or is it normal that the background is uneven?

I seem to remember that is the way it is supposed to look...

thanks, been bothering me for while and with the warranty coming to an end...

das, I just checked for you (while trying out my new home theater projector)... it's normal.

I've noticed the same thing on my plasma and lcd display and I have the same bluray player bdps350.