Ok, how about you post a complete list of your settings. If something is wrong with them, we can tell you right away.
There may not be much we can do for you here since it seems like too vague a problem. While its certainly possible that something is wrong with the TV, I wouldn't expect a warranty claim would get you anywhere either since it sounds like the TV is still working just fine.
However, if this really bothers you then why not try to do a basic calibration on the TV yourself? This is a great plasma that deserves (requires!) a little effort on the owner's part (never assume copied settings are fine). It's very simple and takes 5 minutes. I HIGHLY recommend you use the *basic* D7000 settings posted in the calibration thread as a starting point (forget about copying color and white balance calibration settings). You will need a simple test disc and a bluray player. You can buy the Disney WOW disc or similar, but I suggest AVS HD 709 because it is free: http://www.avsforum.com/t/948496/avs-hd-709-blu-ray-mp4-calibration
All you have to do to get the optimal picture out of your TV is the following:
1. Set cell to 20 (this is a bogus control as lower settings will reduce performance - this was confirmed by a Samsung employee).
2. Set brightness and contrast to a comfortable overall picture brightness for your eyes with typical room lighting (alternatively, start with recommended settings for a D7000, then adjust using only the contrast control to your preference).
3. Use a brightness test pattern (APL clipping pattern if you use AVS HD 709) to adjust brightness following the included directions (this will make sure you do not loose details and color on dark objects).
That should resolve your problem. You can go a little further if you like:
4. Display a color and tint calibration pattern (flashing color bars on AVS HD).
5. Go to the TV's advanced menu, and use the "RGB only" function to select blue mode.
6. Set color and tint according to the directions. (only small changes are typically required)
7. Turn RGB only mode off.
8. Adjust sharpness using a sharpness pattern. (usually something in the range of 10-20 is good)