I have unfortunately been able to reproduce this bug, so I have lost work twice. The first time I included an image in the middle of the text. The second time I included an image at the beginning of the text. Both times I saved work immediately before adding the image. Both times my post was erased from the point I added the image to the end (so in the second attempt I lost the entire post).
Please fix this -- and, in the meantime, to all blog contributors, be careful about adding images.