Steps to reproduce:

1: open the project i have attached
2: open 'test' scene
3: select 'List' gameobject(from hierarchy) and lock the inspector
4: select multiple GameObjects from Project view drag&drop onto open array list

The order in which they get added doesn't match.

Example:
http://screencast.com/t/QS3m0ceVWaD

I have dragged 6 items in order from 1 to 6 and dropped them onto list.
Finished order was: 1-6-5-4-2-3 instead of 1-2-3-4-5-6