sorry, I meant, I remove the Listbox itself, not the items. Then I create a new Listbox, since it takes an array only at the creation stage. I do this when the new array is completely different from the original array.
on your sample script, do you use the array for other purposes? or just to be able to add/delete from the Listbox?
if the latter, to remove the selected item I use
myListbox.remove (myListbox.selection.index);
to remove all (you don't need this if you go with removing the Listbox itself)
myListbox.removeAll();