Schema module reporting on Filebrowser, node_dir_listing.nid is part of the primary key but is not specified to be 'not null'

Just installed
Filebrowser 6.x-2.0-rc12
on D 6.16 and the Scheme module is alerting - on the admin/build/schema/compare screen, I get the following:

* node_dir_listing.nid is part of the primary key but is not specified to be 'not null'.
* node_dir_listing_content.fid is part of the primary key but is not specified to be 'not null'.

There are no Directory Listing content nodes created yet.