Print scale wrong when no external basemap defined

[pcav]

If in the project we add a basemap (OSM etc.), the print scale fits with the current zoom level, and the print zoom levels are in DESC order, as expected:

http://217.57.35.189/webgis/index.php/view/map/?repository=fauna&project=carta_ittica#0

If no external base layer is present, the sort order is ASC (which is unexpected), and does not correspond to the current zoom level:

http://217.57.35.189/webgis/index.php/view/map/?repository=ambiente&project=ecologia#0