Problems Importing from Kindle for Mac

[songsofexperienc]

I'm new to Calibre (version 0.8.14), have a Nook Color, and also use Kindle for Mac. When I try to add books to Calibre from the Kindle for Mac I get the following error:

WARNING: Failed to read metadata: Failed to read metadata from the following:

Kindle.app
Traceback (most recent call last):
File "site-packages/calibre/gui2/add.py", line 129, in start
File "site-packages/calibre/gui2/add.py", line 223, in add
File "site-packages/calibre/gui2/add.py", line 234, in add_formats
IOError: [Errno 21] Is a directory: u'/Applications/Kindle.app'

I had assumed I could just put all my Kindle books into Calibre and convert them for my Nook (assuming no DRM). Am I doing something ridiculously wrong?

Thanks.