Hi Kirk,
I should have used folder instead of catalog.
Here are the steps, I have added the number of images for an example:
Open folder of 244 images
Open find window - search all photos for a keyword
Close find window
F2 to show selected images -41 images remain
Open structured keyword panel
Highlight 11 images to apply keywords to
Apply keyword collection to images
At this point the 11 newly keyworded images remain, the other 30 have vanished.
To get back to my 41 original selected images I have to show all 244 images and start over.
If I want to edit one of the 41 selected images as soon as I save the new file only the original unedited image is still visible and 40 have disappeared.
I hope this explains it.
Kevin