Switching between scenes blocks unity camera

Question

If i run a scene normally in unity 3D it looks nice, but if i switch to it from another scene the camera became blocked and crashed without giving me any error!! Am i missing something? I am working with unity pro 4.5.0 and Nyartoolkit .

Here are 2 screenshot of my two scenes:

the first screenshot is my second scene and the second one is the hierarchy of my first scene !!??

It's the same problem when switching from the first scene to the second scene or going back from the second scene to my first one. In all cases the camera became black as it is clear in first screenshot .