I have experienced the same problem.
I’ve been searching these forums and google for an answer, but no one seems to offer any advice.
I have exported/imported a blog from one server to another. I made sure to check ‘download and import attachments’ while importing… this took forever because there were a lot of images in this particular blog. All the images showed up just fine, but some of the galleries within some posts/pages do not show up. I checked the code and the gallery shortcodes are there, and I’ve checked the media library and the photos exist, but they don’t show up in the gallery anymore… the gallery is essentially empty.
Any ideas on what happened and how to fix this?
Thanks!