Hi Neil,
OK....glad we agree this one is a hoot for mystery code. Ghost in the machine is a good explanation? Did you notice the multiple style sheets?
I honestly thought (and tested) that you didn't need to open and resave a listing to update the template code, i.e. the template code is added at post time by the code builder along with any associated code for a complete codeset. That's why I wasn't concerned so much about the missing code, as the mysterious added code. I was thinking there was a roll update that maybe caught it, which the posting date-time might confirm.
Since the listing has bidders, it does prevent any code updates. White doesn't look bad, so hopefully won't effect the listing's success.
I did test both US and UK for this oddity (they're in my saved lib at last two).
Danno