I just setup my HD1000U for the first time to see where it will be mounted and noticed that on a particular channel that it cut out some of the top of the viewing area.
ie. On MTV high def channel where it shows the rating of PG at the very top of the screen, it only displayed the lower part of the P and G like it's cutting off the top of the display area. It is not projecting the rest off of the screen either as I can clearly see the top border within my screen.
I have a 106" screen and using 16:9 viewing mode, using component cables directly from my Comcast receiver. The display shows that it is in 1080i.