After you modify a TIFF contained in the one-up in Adobe® Photoshop®, the one-up AP file shows the modification but not the Step & Repeat.
After modifying a TIFF contained in the one-up in Adobe® Photoshop®, the one-up AP file shows the modification but the Step & Repeat file keeps visualizing the old version of the image.
This happens for the images placed into the one-up only, it doesn't affect the line work modification and it affects only the preview on the Step & Repeat, as the output (PDF or other file formats) is correct.
Currently there are no solutions for this issue.
To workaround the problem, after the image has been modified and saved on the image editor (Adobe® Photoshop® in many cases), its needed to save again the AP one-up file.