The insert() method of the .ListBox class has several problems.
One of which is that it can crash the interpreter under 3.2.0 and can produce very bizarre behavior under 4.0.0 . An example program that demonstrates this is attached.
In addition, the method is documented as inserting the item after the selected item, if the index argument is omitted. However, it usually inserts before the selected item, often inserts at a point that has no relation to the selected item, and rarely inserts after the item.
In the next release, I was going to simply mimic the previous behavior, even though it is nonsensical. However, because I can crash 3.2.0, I'm going to treat this behavior as a bug and fix the method to behave as documented.