I have perhaps solved this problem. I changed the container (data/appearance) setting to 'reduce or enlarge images to fit', instead of 'reduce images to fit'.
I had used the first setting 'reduce images to fit' because all the images are big, but it caused the problems caused above. Don't know if this is an issue or not.
If these are very large images, I would still say this is a bug as they shouldn't need to be enlarged to fit the container field in that case.
Your files were also forwarded to me by TSTuatara, and I tested here under Mac OS X 10.7.3 and Mac OS X 10.6.8. The images that you included appear fine. That is, I could not replicate the problem. I just checked each field in the Inspector, and they are all set to "Reduce image to fit". Since you changed the setting to "Reduce or enlarge image to fit" in order to make this work, do you get the reduced size again if you change the setting back to "Reduce image to fit"?