I have the same exact TV as you and have the same problem except I only have 1 thin line about 8 inches from the bottom of the screen. I have tried to call customer server and got my issue escalated to ECR and they seem not to be any help at all. Do you have any suggestions?? They tried to offer me this new thing they are doing, which is a rebate program form. Basically I pay for the TV to be fixed and they rebate me a portion of the money. However, there is a list of the TVs that qualify for this and our TV specifically is not on there. The other rebate was to purchase a brand new TV and they would refund me back 10 percent of whatever the TV cost. So a TV that cost 1000 dollars I get back 100 is not worth it to me. I just want the TV I originally bought to be working fine.
To anyone reading: Honestly I will probably never buy another Samsung product again and as long as anyone ask me I and anytime I have the opportunity to bad mouth Samsung I will and tell them my experience. I purchased my TV June 18 2009 and I am writing this June 4 2012 making my TV a few days shy of being 3 years old. In my opinion, televisions this expensive should not be experiencing any of these issues within the first 10 years of the TV. Older televisions were able to work for 10 years plus and we're in 2012 and these supposedly high tech TVs are having trouble after 2 and half. That is a big joke and it's a shame Samsung can't even meet me in the middle to get this issue resolved and keep me as a loyal customer. If this is going to be the case with these TVs manufactures need to provide a longer manufacture warranty with stricter polices because Samsung and any other TV manufacturer should be liable for defect parts that go wrong with their products.
With that said the quote goes you live and you learn and I have learned to never purchase another Samsung product. Next time ill try LG and see if life is really good.