How sub tasks are displayed is confusing
The way sub tasks is displayed within your list when they been assigned a deadline date is confusing!
Surely it makes more sense to maintain the hierarchy, and just display the deadline alongside the task?
Example (displays tasks in hierarchical order) - http://i57.tinypic.com/r29rac.jpg
Example (once tasks have been assigned a deadline date, hierarchy is lost) - http://i57.tinypic.com/2jcxzeh.jpg