Often when altering the volume, the TV will mute and then am unable to have the volume come back on without turning the TV off & back on. Also when turning the TV back on, it will often just come back on with a gray screen - the volume will be on, but just a gray screen. The only way to resolve this is to actually unplug the TV. I know this sounds more like a problem with my TV, but it didn't start to happen until we began using the TIVO system. Has anyone else experienced this?? Is there a fix?