[Jeffhs]

Originally Posted by old_tv_nut

Nope, it's the other way. Crawl on vertical edges (horizontal transitions) like that vertical blue pole comes from a notch filter.

Crawl on horizontal edges comes from a comb filter, especially one that does not have a sophisticated circuit to detect the crawl condition and switch on a notch filter when necessary on that scan line.

My Insignia flat screen (built in May 2011) has a 3Dy/c comb filter, but I haven't yet noticed any artifacts in its picture such as you mention. Perhaps by the time they started using comb filters in flat TVs, the cause of the "crawl" problem had been identified and remedied; that, or else my set has the required circuitry to cut in a notch filter if and/or when necessary.