Not sure if anyone else has noticed but the ability to add a folder (with its inherited sub folders) works differently depending on whether you choose the 'New | Upload Folder' option in the top menu or whether you drag your parent folder from your Windows Explorer window to the workdrive folder.

So what is the difference? It's subtle - if your folders are all empty (ie no files contained within) then nothing happen if you use the Upload Folder menu option; and I mean nothing - no message to tell you no folders were created or anything.

If you drag the empty parent folder from your File Explorer window then no problem... all the folders and sub folders, even if completely empty. will come across just as you wanted.