Import Scapple document into Windows

Using Scapple 1.0.0.0 8th October 2013. Attempts to update produce claims that this is the latest.
Using Scrivener (Windows) 1.6.1.0 31st October 2013.
Using Windows 7 Home Premium 64-bit. Latest updates installed.
Instead of a Draft folder, my equivalent file is called Manuscript.

Scapple Manual in Section 9.5.4 clearly states "you can simply drag the .scap file itself into Scrivener’s binder (placing it anywhere except in the Draft folder)

I have tried this using several .scap files and none has been successful.
Any ideas where the problem might lie?

Taking the same .scap file, I selected 50 notes and successfully dragged them into a folder in Scrivener’s binder.

Do you have Scrivener set up to allow all file types to be imported into the Binder? Check in the Import/Export options, and see if “Imported supported file types only” is turned off.