Adjusment made in Develop mode not...

I made several tone adjustments to an image in Develop mode. When I switch back to Library mode the changes are no longer visible in the preview of that image. I switch back to Develop mode and the changes I made are visible. I can also see the changes in the history palette. Go back to Library and they are gone again.



I adjust several more images and the changes made in the Develop module are visible when I switch back to Library. Then I run into another image where the problem arises again. The seemingly random nature of this is very frustrating. Any idea what is going on? Could those files have been corrupted along the way? Is this a LR bug?



LR1.0 on Intel iMac OSX 10.4.9 2 Gb RAM
Adjusment made in Develop mode not...
What type of files are they Manuel? And have you rendered previews?
Adjusment made in Develop mode not...
Geoff, the files are NEF (Nikon Raw from a D200). I have rendered previews. I just went back to make sure. I selected the images and clicked on render 1:1 previews (library/previews/render 1:1 previews). Nothing really happens so I assume that they had already been rendered.