This was reported in the Debian bug tracker, as http://bugs.debian.org/443722:

"Since a fair while, I've been starting to see corrupted pictures in
f-spot. It took me a while to figure out what was going on, however. I
have now.

I'm attaching a (resized) corrupted picture, which became corrupted once
I added a tag to the picture. To make it clear: I had been browsing
through my picture collection, and everything appeared right on first
sight. When I added one particular tag to the picture, suddenly the
corruption that can be clearly seen, occurred.

I should note that sometimes the same corruption occurs in the vertical
sense as well, and that it sometimes also involves color changes."

The submitter was using f-spot 0.3.5 on powerpc, and I don't have the hardware to reproduce it. It might be possible to use qemu, of course. In a later comment, he claimed to have seen the same problem (but much less frequently) in digikam, which might suggest the problem is in libexif or some other shared library.