Temporary burn-in on a LCD, last legs?

[Bocsius]

I have a Samsung LCD HDTV just a little over 3 years old. I swear I've never noticed any such thing before, but I'm starting to see some burn-in that typically fades over 10-15 minutes or so. I first noticed it while playing Final Fantasy XIII. Then noticed it on the pause screen in Dragon Age 2. Since both were from playing 360, I thought maybe it's the screen, but maybe it's those games and/or the 360 causing it. Today, I noticed it after flipping the TV away from PTI (the "Rundown" was burned in).

Given that I never noticed it before, say, a month or two ago, is this a sign that (a) the TV is starting to age or (b) I'm just totally oblivious and it has been happening the entire lifetime of the TV?

For specifics, it's a 40" Samsung 1080p LCD, 60hz refresh rate, bought January 2008.

[Robo]

If there's no weird fuzziness to the picture or anything, it's probably been happening the entire time.  AFAIK, certain LCD panels are more susceptible to image retention than others.  It's perfectly normal in most cases.

You don't have the contrast or brightness turned up really high, do you?

[Mupepe]

Probably just never noticed it before.  It's one of those things that when you see it you can't unsee it, like bowing on a crt or the rainbow effect on a DLP.