C36v23 Discoloration On Top

[mar1454]

does anyone else have this problem. when playing vcr tapes bought or rented thru antenna channel 3 or video input you intermittenly get a discoloration on top of picture sometimes half way down the screen. dvd's ok cable service ok only vhs tapes especially the movie THE PATRIOT.
already tried different vcr.

[FullBandwidth]

Only a guess (haven't played many tapes at all recently) but could it be a tracking issue on the VCR? The Zenith's digitizing circuitry may be responding differently to the signal than an old analog TV would.