             @machine_list.register_machine_callbacks callbacks
 
         destroy: =>
-            machines.off()
-            @machine_list.off()
+            machines.off 'add', (machine) => @render() if machine.get('datacenter_uuid') is null
+            @machine_list.off 'size_changed', @ml_size_changed
 
     class @AddDatacenterModal extends UIComponents.AbstractModal
         template: Handlebars.compile $('#add_datacenter-modal-template').html()

            $(event.currentTarget).tooltip('show')

        destroy: =>
            @model.off()
            directory.off()

    # Datacenter list element
    class @DatacenterListElement extends UIComponents.CollapsibleListElement

            @machine_list.register_machine_callbacks callbacks

        destroy: ->
            @model.off 'change', @render_summary
            directory.off 'all', @render_summary
            @machine_list.off 'size_changed', @ml_size_changed

    # Equivalent of a DatacenterListElement, but for machines that haven't been assigned to a datacenter yet.
    class @UnassignedMachinesListElement extends UIComponents.CollapsibleListElement
