Horrible tv pixelation at night

When I watch TV at night (after 8:00pm), reception is consistently bad.  I'm trying to watch a movie now and with 20 minutes left in the movie it is frozen.  Half of my DVR recordings are unwatchable because of this problem.  I have been adamantly opposed to satellite services but this problem is making me reconsider (especially with the annual 10% rate hikes from Cox.  Is anyone else experiencing this problem?