bad at faster frame rate

Unfortunately my old Panasonic plasma television showed a growing red fog. As I was told everywhere, plasma was dead and I was very pleased with my old unit, I jumped at this model. At first I was thrilled. But then came the first fast images. A marked drop to my old plasma device (no matter on which source the images were recorded)! I wanted to change it, but I recognized in more expensive devices (Panasonic) the same problem. I'll keep this TV because of the price anyway, but wait for the next Genration and then ...