Why do some actors appear in front of others?[SOLVED]

Why do some actors appear in front or behind others? How can I control that? I want to use some actors with no collision shapes as appearing in front of other actors.

It would be a lot worse if the actors would just blend with eachother
This solution worked before: http://community.stencyl.com/index.php/topic,22829.msg131802.html#msg131802

in the scene you're working on, go to the Layers tab in the bottom right corner & press the + button to create a new layer. Then place your actors in order....place the ones you want to be in back on layer 0, & place the ones you want in front on layer 1.
It should help.