Syncing folders not 2-way?

[rathomp]

If I import a file folder (either by drag or wizard) then I get the UR item being the folder and child items being the files in the folder as expected. If I add a file to the folder (externally) and sync (ctrl+F5) then it shows up as another child.

However, if I delete a file (externally) and sync then the UR child item remains for that file although it has no valid URL. I guess this is by design but was not expected. Is there a way to have the folder sync work in 2-ways?