P: Reproducible spurious "Metadata file needs to be updated"

Many people have complained about spurious "Metadata file needs to be updated" icons appearing on thumbnails in Library mode. That has happened to me off and on for a year with LR 3. I now have a small 16-image catalog for which this happens repeatedly. No matter how many times I select all the thumbnails and do Metadata > Save Metadata To File, the needs-updating icons reappear very quickly, usually within seconds. The metadata is getting written to the files correctly -- it's just that LR doesn't think it has.

The test catalog was created with LR 3.5RC on Windows 7 by exporting from my main catalog (also exhibiting the problem).

Adobe, you can download the zipped folder containing the complete catalog and images from:

http://dl.dropbox.com/u/21811200/bugg... (111 MB)

Please let me know if you download it, so I can free up my Dropbox space.