Well from what I could google on that model I would say your TV is up-scaling the Video to 1080p because according to the specifications the Video resolution is 720p. Up scaling would cause txt to be blurry give the fact that TV's are not really meant for viewing txt anyway. If Windows is showing the native resolution as 1080p that would be incorrect it may accept 1080p but the native resolution is really 720p anything else is just scaled up or down. I would try to set the resolution at 720p no scaling and see if that helps any.