Seems the offending image was somehow corrupted as far as my batch utilities (including "make Zoomified") were concerned. Opened the file in Photoshop, made a small change, re-saved it, and the script ran fine.
I also put a check in the code to issue an alert but continue processing should it hit a similar snag.
Pages at http://www.uvm.edu/~waw/landscape now utilize thumbnails — or display broken images if the thumbnails doesn’t exist yet (we’re up to LS03329_000 as of 1:34 PM Monday).
