Our products were imported using Magmi and the swatch images set using the media_gallery field of the Magmi CSV file. After the import completes, the swatch images are seen correctly in the product catalog. When viewing the product in the public site of the site, the swatches are not show. When going back to see the product catalog, the swatch images have disappeared.
If we add the swatch images manually through the product catalog the swatch images remain as expected.
After the import is complete the product looks like this from the admin page:
Then going to the public view page we see this:
Going back to the product catalog page we see that the swatch images have been removed:
Refreshing or not refreshing Magento index has no affect either way. All caches are turned off.
Magmi image import settings are: