I believe this issue was fixed with a firmware update. I purchased this exact model last week and am extremely happy with it so far.
I am looking to buy this tv but I have read a lot of reviews of people having problems with them. Many complain that the tv will reset or turn off my itself after a while. Did samsung fix the bugs on the newer ones or is it likely that I will have all these same problems?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic