Managing attachments messes with ImageGalleryPlugin

ImageGalleryPlugin Version: 4425 (2009-07-03)

I have a weird error probably due to version control after manually changing image attachments that are displayed in an image gallery. For me it's reproducible as follows:

1. Load up image a.jpg to a page with an %IMAGEGALLERY%
2. Via "Attachments" -> "Manage", change a.jpg by uploading b.jpg instead without changing the comment or anything else
3. Repeat with image c.jpg instead of b.jpg
4. As a result I get the following: ImageGalleryPlugin now correctly shows the thumbnail of c.jpg. Clicking on that thumbnail takes me to slideshow view, which is displaying b.jpg. Clicking on that once more takes me to plain picture view, showing c.jpg again.

Note that sometimes I've had errors even after changing the picture only once, and sometimes the thumbnail view was faulty, too. I have not been able to reliably reproduce these phenomena. The above procedure however seems to always reproduce the problem.