NTSC dot crawl is bad

[lnx64]

I have a Commodore 64 monitor, a clone, Teknika MJ22, that I'm using for my father in the kitchen. It's hooked up to the cable boxes composite out, and it has always worked and always had a great picture. One day, something changed, in a very odd way. All solid colors are basically dots, kinda like a checkerboard. But all black and white areas of a picture, are sharp, REALLY sharp. Any ideas on what's going on here? Here's a picture of what it's doing with the colors. Those colors are supposed to be solid, not dots.

http://i.imgur.com/9dBJPkt.jpg