Samsung 7000 3d Blacks out for Seconds

Purchased Samaung 3d TV in Dec from Best Buy. Noticed immediately that was blacking out for seconds and turned itself off once but came back on when turned back on. Talked to manager at Best Buy and they had never heard of this but agreed to exchange TV. Got new one 2/15/11 and it does the same thing. Turned itself off this AM and had to be turned back on and is still blacking out for seconds. Have had DISH reset but still have the problem. Samsung definitely has a problem. TV has beautiful picture but this should not be hsppening. What is Sumsung going to do about this?