I have an HP Pavilion Laptop connected to an Insignia surround sound receiver via HDMI, which is in turn connected via HDMI to an Element 46" 1080p LCD.
Until I get my HTPC built, I've been using my laptop to watch movies etc, with no problems. The picture was great (info said 1080p), etc. I used my TV as a monitor numerous times over about 2 weeks. Then, randomly today, when I turned on my TV it was overscanning (I couldn't see about 3/4ths of the lower task bar or the upper toolbars in programs, etc).
I went into the settings, and they were the same as they've always been. I went through all the zoom settings, and none of them helped.
I finally changed the display resolution on my laptop to 1080i, which fixed the overscanning, but the display is now noticeably more blurry.