I bought a new Plasma TV, now what?

[aich75013]

I have a Samsung and have noticed some slight burn in from leaving the guide for the satellite up too long. I can see the grid pattern later. It goes away but worried me.
I since found an option in the menu that is supposed to shift the pixels occasionally to reduce this problem. It was turned off by default so it is now turned on. This was recent but I haven't noticed the grids since.