I have a gallery of photos that have white borders.  When Juicebox generates thumbnails for them, you can see the side or top borders on the thumbnails, and the thumbnail gallery looks sort of odd/cluttered as a result.

I created thumbnail images that don't have borders and put them in the Thumbnails folder, deleting the ones that Juicebox created. However, if I hit Publish, Juicebox generates its own thumbnails and replaces mine. Is there a way to tell  Juicebox not to replace the thumbnails in the Thumbnails folder? thanks!