Problem encountered by Ally on the Beta Cluster and reported on the glamtools mailing-list
Quoting her email:
When I’ve uploaded larger files (2500px) to the Beta cluster, the image re-sizes to the smaller, 500px version whenever I try to view or download the image at full resolution, despite all indications being that the current version should be the larger format.
I’m not sure whether this is an issue with the Beta cluster or with the Toolset, or if it only has to do with uploading subsequent versions of files.
Example link: http://commons.wikimedia.beta.wmflabs.org/wiki/File:Imaginative_depiction_of_the_completed_Forth_Rail_Bridge.jpg
Full thumbnailing is possible though: