Or maybe you need to turn on Library / Library / Show Photos in Subfolders?
I just tried and still no luck. Thank you for your help.
First try restarting Lightroom and/or your computer, if still no go:
Try renaming your preferences file, if still no go:
Try a backup catalog.
I think either Lightroom itself is wrapped around it's axle, or your catalog is on the blink.
You can always try re-installing Lightroom, although my experience is that the problem is more often a data file than a program file.