Both. However, after talking to HP, they said I really should exchange it before going any further. I did, and of course, the problem is gone! So is the "failure to recognize USB" port problem.

After opening the new printer (the other was only three days old), I realized that the first had been repacked... albeit very, very carefully.

The "track" problem involved the paper-feed "fork" plate, which had too shallow a tolerance between itself and the paper feeding though. The tines of the "fork" were dragging on the paper. ... Mike