Which campaign are you working in? I have retitled one "Autumn Sale" but I realized that it doesn't have SALE written out in all leaves...could you retitle the one that you are working on? To name it in the editor you can click on the words "Untitled Mailing" in the upper left hand corner. That will give you the field to rename it. Post here and I will check into the issue.
The other thing you may want to do, is clear your browser cache. It could be that the cache is full and so it doesn't have room to save the changes. Let me know if you need to know how to do that!