In the screenshot below, I selected the first two objects and then I clicked the delete icon for the third object.
I am prompted asking if I want to delete the object 0_win_usage_disk_c:
I click Yes
When the screen refreshes all three objects are deleted. The objects that were selected should not have been deleted.
An unusual set of circumstances and I avoid this activity since I discovered it (we all work in strange ways
Nagios XI 2009R1.4 running on a VMware VM on an ESXi 4.1 host.