Topaz Video v1.0.4 - when enhancing video 640x480 or 768x576 to 1280x960 (minimum) using Starlight (local rendering), there is dark stripe in the bottom of the video. The original doesn’t have this atrifact.
I have seen the same thing, but not consistently. Sometimes it is there, sometimes not, which makes me think it is related to the original video even though it is not visible there.
In any event, you are not the only one still seeing this.