The "views_gallery.info file has:

dependencies[] = "nodereference_url"

instead of:

dependencies[] = "node_reference_url" --- NOTE THE UNDERSCORE.

which will indicate that the Node Reference module is "missing" even though it is not. This keeps
the checkbox greyed out for the views_gallery module, so it can't be enabled.

It is this way in the 6.x-1.3 version too.