I have the same problem as some others but haven't found the solution (this thread is over a 1000 posts and I've only read about 200!!!).....
additional images don't show up in the product info page.
The other images are there when I turn IH2 off but disappear when it is on. I can also see them in the IH2 Manager.
This is a fresh install/upgrade from 1.2.7 where the old version of IH was working fine.
One other thing I noticed: for the one product that I added images for using IH2, when I look at it under IH2 admin there are no "delete" buttons under the med and large sizes. All the other products (which were added under 1.2.7) have "delete" buttons.
Help!
