I am currently working on a patch for version 2.5 that should (hopefully) address a savegame bug relating to thumbnails. If you get a crash log, please report them to me if possible.
Thank you for your patience!
Edit (02/27/14): Seems like I am running into even more bugs. Huge thanks to those reporting them to me! More likely instead of a hotfix, this will end up as another version release once I am done.