Last modified: 2007-01-22 16:40:21 UTC
It is my understanding that using thumb.php as above (see URL) should be enough
to force it to re-render the image thumbnail. Am I mistaken? Is there something
else that needs to be done?
You are mistaken. thumb.php returns the existing file if it is present.
Use ?action=purge to purge thumbnails.
Note that there are presently some issues with Commons, and some thumbnails may
not be cleared.