Where are the resized/thumnails/etc files stored?

I have uploaded some image files to my gallery (I checked using a symlink), applied a watermark and all but forgot to modify some exif info.
So I modified the exif info in the original image, I checked that the original file has it ok, and when I refreshed the photo in the album I still got the old exif info. I checked and in my albums directory all the imanges are symlinks to originals.
Also, I clicked on clear saved pages on the performance page and ran "Build all thumbnails/resizes" on maintanence.
What else do I need to do to get the changes showing?
Or, where are the resize/thumbs stored so i can apply the exif changes directly to them?

thanks

that would most probably work, however, I see it has 2 bugs that annoy me.
I guess I'll go with delete and re-upload.
thanks.