[Away3D] Problem with displaying line segments

[Dexter]

i have a problem with displaying lines on the scene
for example, i have two trident objects.
http://s7.postimage.org/5lfj1hoej/image.png

but when i add some objects on the scene, this trident lines begin to
behave strangely.
http://s7.postimage.org/6qj8hq6kr/image.png

i tried to change view renderer and clipping but it doesn't help me.
how can i fix it?

thanks!