Android -自定义ListView适配器-多选择删除- Indexoutofbounds -为什么?

I have a custom Listview using a adapter class to extend ArrayAdapter of a Item class. I have the ability to change between choice modes of NONE,Single and Multi. This all works fine. What I am trying to implement now is a method to removes items from the list view (and adapter) with multiple selection when in the multi choice mode. However I get IndexOutOFBounds Exceptions when doing either of the following; 1) remove last item in listview in SINGLE choice mode (Note: anything before last item remove ok) 2) In multi selection choice mode I once again can not remove last item 3) again in multi selection mode I can remove single selected items before last item but 2 or more selections result in index out of bounds errors again.I have a custom Listview using a adapter class