drop-down list order of "Planned For" attribute

Hi,

I have a question.
What does it determine the display order of the drop-down list of "Planned For" attribute?

I've thought it is derived from the order of the timeline definition in the project area, but it seems not.
Also,the order displayed in "Choice of the iteration" View when I click more... is different from the original one in the project area.
The logic behind what is initially displayed in the drop-down list is discussed in the following forum topic, but I couldn't get the same behavior.

Planned For preferences?
https://jazz.net/forums/viewtopic.php?p=49580


the timeline definition in the project area
-release1.0
--requirement(finished)
--design(current)
--implementation
--testing
-backlog

the iterations are initially displayed in the drop-down list as follows
unassignment
requirement
->design
implementation
release 1.0
backlog
testing
more...

the all iterations order in "Choice of the iteration" View are presented as follows
-unassignment
-backlog
-release 1.0
--testing
--implementation
--design
--requirement

Is it possible to be displayed the same order as the timeline definition in the project area ?

Please help me! thank you!