Raycast with multiple camera's in scene

Hi,

I have a scene with three camera's. One main camera and two camera's used for render textures.

My problem is that when I try to raycast from the maincamera it only detects it in the most right "third" of the screen. When I set the normalized viewport rectangle width and height from the two side camera's to 0, the raycast is detected all over the screen. Downside is that my render textures now dissappear (Which is ofcourse easy to explain).

Can I solve this, so I can create a raycast all over the screen, but still get my render textures full sized?

(If you need more information, please ask, I can post everything if necessary)