Currently the contents in the dashboard are grouped first by their "show in menu" option - contents which have "show in menu" checked will be displayed first, and others will be grouped at the bottom. After that, those links which have "show in menu" checked are ordered as set in "Manage links" section of the administrator panel.

This is done even if you are actually not using automatic menus [ http://www.cubescripts.com/instant-update/wiki/usage:auto_menus ] and it can not be changed at the moment.