I wish I could help you. I've been through 8 TVs over the past year from different retailers trying to buy a new one. They've all had some problem, from buzzing and flicker with the plasmas, to blue shadows, banding, DSE (dirty screen effect), flashlighting, or overall poor uniformity on the LCDs. Either I'm super-unlucky or TV's now just suck. The irony is that they usually look/sound fine in the store which gets your hopes up, but of course when you get home with yours and open the box you can see or hear a problem within minutes and you get sick to your stomach. I am the type of person whose eye is drawn to the imperfection the whole time I'm trying to watch the set, so I have had a hard time settling for flaws on my expensive new TV.
I'm going to try a direct-lit LED next because getting an edge-lit without uniformity issues is harder than winning the lottery, apparently. Here we go again!
I've dealt with Best Buy for most of these sets and they have always been great about it. Thanks to their "Perfect Match Promise" they have come to my house to pick up the sets every time without charging me. And yes, every time you return a set it is a gamble that you will exchange one flaw for another. (Yay! No DSE. Oh wait, are those dead pixels? $#!+) I would advise you to ask Future Shop what would happen if you exchange and the new set is no better or worse. They should be able to tell you if it will be a problem or not.