From a quick skim around the WWW, it appears Apple is to blame for old .mov files not working. Apparently they stopped updating Quicktime and forgot to tell anyone and it became a malware haven. Thanks, Apple, you dudes are truly... the genius bar.
Anyway, this means .mov files that I convert to .mp4 don't automatically loop unless I save the .mp4 with a javascript controller. (The old Quicktime had the option to make .mov files loop.) Too much hassle, so for files such as the above, I converted the .mov to .GIF and specified "looping." This destroys one of the subtle charms of the piece, which was that the Quicktime player struggled with a short (.4 seconds) loop and you got erratic repeat times in the above, causing the vertical blue-grey bands to drift from side to side. The browser plays the GIF fairly uniformly. Anyway, too much info. The post explaining the project above is on my 2001-2007 blog.