Fixing thumbnails on only a few files

[ikaruga]

Here's the scenario. I uploaded about 7000 photos the other day to my new coppermine.
Lo and behold I soon discovered that coppermine doesn't autorotate photos from exif data. The result was several 100 files, randomly scattered in my collection, with the wrong orientation.
This isn't my problem, though.
After searching the web, I discovered a little utility called jhead that can fix the orientation for me.
So I went and wrote myself a script to fix the rotation of these files and also fix the orientation of the thumbs and intermediate pics.
HOWEVER, here's where the trouble begins:

• I downloaded the files to my computer, and sure enough they are indeed fixed.
• The coppermine gallery is another story. The intermediate pic displays fine, but the thumbnail is a squashed square and the link to the full-size photo points to the old photo.

How can I fix this without running the Resize thumbnails Admin utitlity? Since I have 7000 photos that seems like a big waste.
And why is the full-size photo coming up wrong? The link actually points to the old photo. How is that possible? I changed the file in the albums directory.

[Nibbler]

Admin tools also has an option to reload image dimensions. Make sure you clear your browser cache or force reload the page after changing images.