Solved:
OK, as I said in the last post this is a secondary node with a master storage node for images. I had updated the image and uploaded it directly to the secondary storage node, but the main storage node at the central office still had the previous version of the image. Jus to test I uploaded the image file from the secondary node back up to the main node and tried to multicast again. It worked at it should! Note to self: Always upload to main storage node fresh images and let them replicate down to the secondary nodes at the schools.