That would likely be an affect of the AutoMotion Plus. The good news is that this is adjustable in the picture settings menu, and you can choose to lower the effect (or turn off the processing altogether), and is adjustable for every input.

For instance, if your HDMI-1 Cable box looks best with it on MED, and the Blu-Ray player looks great with it on HIGH and the game console looks best with it on OFF, each input is specific with those settings.

Hope that helps.