I finally was able to capture some visual evidence of what is happening to me when the filament feeder clicks. The model on the left had the clicking problem, I believe, starting at about 1 cm from the top. I was actually gone when it started, but it was clicking almost continuously when I arrived back home. The model on the right did have a bit of clicking at one point in time, until I applied more WD-40 to the dremel pad. You can see the clicking Just to the left near the top of IV.
If you look at the second image, you can see what the clicking is doing to the infill as well. My infill is normally very pretty.