Rendering to Texture

I am trying to render different viewports to the same render texture.

From the document:
It says, When rendering into a texture, the camera always renders into the whole texture; effectively rect and pixelRect are ignored.

As I try it on two different machine, a desktop and a laptop, it seems to be giving different result.

it is ignored on one pc but not ignored on the other.
The difference is one is personal the other is pro.

Have anyone also notice this?

 

As I spend more time investigating this problem,
I find that actually this is project dependent.
In the project I created myself, I was able to do multiple view port, but not in some sample projects.

Does any one have any idea why is this case?