I am having a problem with thumbnails of psd files showing up in the Organizer for PSE 9 for mac. I get a picture of a ripped file in place of the thumbnail. If i bring that file into the editor I can see it fine, it just won't show me a thumbnail in the Organizer.
Select the images in which you are not getting the thumbnails, then EDIT>Update thumbnail.
It should update the thumbnails.
If the issue is still there
Go to the catalog location (to see the catalog location, Click HELP>SYSTEM info>Catalog location)
Here you will find a file called thumb.5.cache, rename it to thumb_OLD.5.cache or move it to desktop.
Relaunch the PSE it will recreate the thumb.5.cache and hopefully it resolve the issue.