horizontal lines appear on camera pan/zoom

I've done a successful camera zoom/pan of a scene but want to zoom more than I did so I'm doing the scene again and have run into this problem.  Anytime I add a camera to the scene and do the zoom/pan, I get a horizontal line on the scene on one or more of the frames.  They show up in the zoomed in view (and in the media file I create) but when I zoom out the view, the line isn't there.  Here's the zoomed in view of a frame

Here is the zoomed out view of that frame

When I create a media file and run it, the horizontal line flashes on the screen on that frame.

I've tried it a number of times (from scratch) and sometimes I get one line, sometimes more than one.

Hiding my layers, the line is on the background layer.

Any ideas?