I bought my new LCD about 2 months ago (Sony KDL-46Z4100/B), and first one was completely screwed... after about 2 hours of watching it everything went green and then scrambled pixels every where... next one it took me a few days but realized it must have been out of the box before as it had 2 huge scratches that I could only see when I shone a flashlight on it (take a flash light to the store)... but once I saw them I could look for them and see them slightly when it was off or a night/dark scene... so I took it back and went to the storee flashlight in hand... my current one is beutiful looking and unmarred... so don't be to upset... I was pretty put off by my first few weeks of ownership as well, but once you have been watching it for a few weeks and not having troubles you'll forgive all the pains in the but you had to go through.
you may want to search here for your TV. lots of tips on tuning and things to try for my model...
http://www.avsforum.com/avs-vb/showt...php?p=15162848