If you have a satellite box and/or DVD player with DVI ouput jacks, and your DVI input display is across the room, you may have run into a problem as I did, namely, the image has sparkles. Like this:
The sparkles are due to the DVI cable being too long for the small DVI output voltage in your sources. Each sparkle is a pixel that is white instead of whatever color it is supposed to be, and is a missing bit of information in the stream.
It is sort of like the "snow" that we saw in our old terrestrial TV broadcast images when our antenna was too far away from the TV station.