Ok, so I may have come up with something. I was originally printing a square photo, which gave approximately 3" of margin on each side of the 17x22" sheet. I then tried a photo with a different aspect ratio which had the photo start approximately .50" from the edge, and it worked perfectly. I then tried another photo with the same aspect ratio and it worked perfectly also. I then put the trouble photo back in the printer with the square photo and it gave me the same problems.
This sounds unlikely, but is there some kind of sensor in the print that is bothered by the all the white space for some reason? That doesn't make much sense to me, because how is this any different than printing a regular print? Although I seem to have created something repeatable.
My next step would be to trim the photo to give the .50" of white space on the edge and try again. I could also try printing a new one with the square image not centered, but all the way to the top.
Does any of this make sense?