I know that C1 docs recommend moving folders from one drive to another internally in the Library panel. So I was moving them, one at a time (sure wish I could select several at once). Some of the folders popped up a message warning about moving Thumbs.db and no matter what choice I made (move or don't move) it still went through the process of importing the moved images as if they were brand new and they were no longer connected to their edits! YIKES.
This didn't happen if a thumbs.db file wasn't in the folder. It went as expected.
Turns out FastStone Imageviewer leaves a thumbs.db file in the folder. It appears that C1 is using a Windows Explorer call to actually move the files when you drag and drop from within C1. The reason I suspect this is that the warning dialog about moving thumbs.db is the same you get if you copy/move folders in Windows Explorer. My hypothesis is that this 'unexpected interruption' confuses C1 and instead of linking to the moved files it performs an import.
The way I got out of this jam was to find a recent catalogue backup and then use 'locate' to relink the files in the moved folders. That worked. Now I believe moving the folders OUTSIDE of C1 (with C1 shutdown) and then relocating the folder is the safer method.
Has anyone else seen this behavior? What is your preferred way to move folders to keep them linked?