Issue parent/child relationships are not respected

[angelatlarge]

In my project I have a lot of subtasks. It appears that better gantt chart does not respect the parent child relationships in the display, see

http://i.imgur.com/hbc5ZNK.png

Without the plugin, the parent/child relationships are displayed correctly. Issue 19 has issues 27, 28, 29, 30, 40, 41, 42, and 43 as subtasks. In Better Gantt Chart #20 is displayed as a subtask instead.

Thank you!

[kostyfisik]

Same problem with "Smart sorting" option switched on. One more illustration how it looks like. №1688 has two subtask issues: №1770 and №1769