DisplayName vanishes

I have a routine that takes the DisplayName property of a FolderItem and places it in the Window.Title

I noticed that sometimes is “vanishes”… so I tracked it down…

I can examine the FolderItem object… and AbsolutePath, NativePath,ShellPath and URLPath are all there, and populated correctly (including the filename)

But DISPLAYNAME is blank… but NAME is the correct value. [and LR says under OSX to use DISPLAYNAME]

This does not always happen… sometimes it is correct

Anybody else ever see this?