OK. I think we need to test whether or not there is any corruption in this particular project, or whether the issue is with the image.
Create a new blank project and insert the same image from your original source files. Then publish or preview. Is it present then? If not, the issue is in the image. Try converting the image to a different format (e.g. PNG or BMP) and reinsert.
If the image shows in the previous test, then it looks like your current project may have become corrupted. Try copying and pasting all slides into a new shell project of the same dimensions. If that doesn't shake things up and show the image, rebuild the project again from scratch.