Extended PDF Metadata - Comments and description

Am a bit confused about 'Comments' (setting Metadata, ctrl-M) versus 'Description'-column in details view.
In File-Properties and Metadata the text is under 'Comments' whereas in details view it shows up under Description and the comment column is empty.

For good order's sake I have used File Meta Association Manager to add some fields to the properties of PDF file. Maybe this is the cause?

The Description column displays various information from multiple sources in one place.

Okay, thanks.