While adding an object to the Objects list (Object→New Object) if there is more than one possible result and one already existing in the plan is selected from the Search Results window a pop-up window is displayed upon clicking "Add Selected" that warns about duplicity:

"Selected objects include IDs already present in the planning list. Include them?" Clicking NO, a second pop-up window appears that shouldn't:

"Really replace the 1 selected object/s?" If clicked NO nothing happens but if YES is clicked the object replaces the one selected in the plan. It works OK but shouldn't appear if NO is selected in the first warning window.

Fixed.