Lightroom :: Folder Synchronization Does Not Work Properly?

I recently upgraded to LR4 (on OS X 10.7.4), but this problem was also present in the previous version.I usually move photos around using the OS X Finder (as sometimes they are outside my Lightroom catalog). To make the updates available in Lightroom I've always used the "Synchronize Folder" option. It did work perfectly for some time, but lately that is not the case.For example, here's a folder called "Parents".I added some photos to it using Finder, then tried to sync it.

Normally Lightroom would find the new files and allow me to import them. What happens here is that Lightroom wants to remove all the photos that already exist in the folder (and Lightroom catalog) and then re-import all of them + the new ones.

First I tried to select "Import new photos -> Show import dialog" and import only the new photos. That didn't work, too. (Please see the image below; however in this sample I've chosen to import/remove all of them).
 
As you can see Lightroom re-imports the folder as a top-level folder, but it should be a subfolder to "Other". When I try to move it manually to "Other" I get an error message that tells me that I can't do that as a folder with the same name is already there.