I just tested a folder of about 150 images and added them all to a catalog. For me, the circle turns green immediately after the operation finishes. I did this by selecting all the items and then choosing "Include Selected Items" from the Catalog menu. Since there are several ways to add items to a catalog, can you specify which method you are using? Other than the green circles, do the other indicators of a successful catalog addition happen (for example, does the folder path for those files appear in Browse tab or if it was already in there, does the file count for that path increase despite the green circles not appearing)?