'save' icon does not notice all changes.
Steps to reproduce:
1) Start new project
2) Add 3 new tasks (just hit new task 3 times)
3) Save
4) Select task _1 and change order with up toolbar button.
5) Observe that the Save 'disk' icon does not appear as if no change occured. (Note that Undo does work, so changes were tracked.)
Moved here: http://code.google.com/p/ganttproject/issues/detail?id=99