If AJAX happens on form, Colorbox does not close

I am using colorbox node to edit nodes from a calendar. On a standard form, it works perfectly. But if you use ajax on a field, for example uploading a file or image, or adding a new field collection row, then the colorbox does not close after save, yet the node is saved. If you launch the colorbox again, you see this error...

Notice: Undefined index: #ajax in ajax_form_callback() (line 395 of /mysite.com/includes/ajax.inc).

Steps to Re-create

1. Add a new content type "test" with an image field, and a standard text field.
2. Create a colorbox link to /node/add/test
3. Click the link to launch the colorbox and enter text into the text field only, and click save. The colorbox will close and redirect the user to the new node. (Works perfectly)
4. Add another "test" node, but this time, upload an image into the image field.
5. Click save, ajax saves the form, but the colorbox does not close, and the page does not redirect to the new node.