Flare Fx and colliders

Hey folks, i've had runned into a little issue and i couldn´t find anything on the forums about it.

For some reason my flares show through colliders, my flares are simple plane meshes with a material using the Fx/Flare shader.
I also tried to swich the "flares" layer to TransparentFx while everything else was on Default but it still draws the planes over the default cube with it´s Box Collider. Im sure im missing something but i can´t figure out whats it. Any ideas?

 

If i add a point light with a flare a box collider block the flare but not the box using the flare fx shader (and this same box won´t blocks the point light flare), The problem is that the shader appear to double side the plane, maybe there´s a way to change it? or im not supposed to use that shader to make headlight and taillight effects?