Line Renderer Physics

If you wouldn't mind I have two questions.
1. http://forum.unity3d.com/threads/line-renderer-collision.332991/#post-2157152

The other is similar. I have stationary objects in my scene and other objects that spawn and move on screen. The user can drawn lines via line renderer and then I add a box collider to that line for collision forces.
There are rare glitches in the collisions. Sometimes if the line is large enough, objects will pass through.

How should I optimize the line? Interpolation, Kinematic, etc.? I want it to be quick, but work well as a collider.

Thanks, all!

 

1. answered in your other post

2. sometimes if objects are to fast, they will pass a collider. a rigidbody with continoues collision detection is working in most cases for me

finally it sounds for me your objects or your hole scene is scaled realy small