raycast wont hit collider after using NGUI?

Question

after turn the main UI framework to NGUI, we found that We couldn't hit object with collider anymore with following code which was working fine we not using NGUI:

private void checkRayCast()
    {
        if ((Input.GetMouseButtonDown(0)))

        {

            Debug.Log("shoot ray!!!");

            Vector2 point = Camera.main.ScreenToWorldPoint(Input.mousePosition);

            Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
            RaycastHit hit2;

            if (Physics.Raycast(ray, out hit2, 100))
            {

                //this should hit a 3d collider
                Debug.Log("we may hit something");
                Debug.Log(hit2.collider.gameObject.tag);
            }

            RaycastHit2D[] hits = Physics2D.RaycastAll(point, Vector2.zero, 0f);
            if (hits.Length != 0)
            {
                //this should all 2d collider
                Debug.Log(" ohh, we hit something");

            }
            else
            {
                Debug.Log("you hit nothing john snow!!!");
            }
            //if (hit.transform.gameObject.GetComponent<Rigidbody2D>() != null)
            //{

            //}
        }

    }

And we found that we could not hit a 2d collider or 3d collider anymore

Here is the target object's inspector:

EDIT

After following @programmer 's advice and resize the collider to a very big one, hit was detected(thanks, @programmer)

But the collider was changed to so big that it not event make scene. And We should find how big this should be now.

• before resizing the collider in the scene note the green border which indicts the collider size made scene

• here is the one that the collider works, but should be unreasonably large:

Answer 1

After digging around And I have figured this out:

The trick is we should use UICamera.currentCamera instead of Camera.main to shoot the ray when we using NGUI.

If we click here in the game view to shoot the ray:

And If we add a line like:

Debug.DrawLine(ray.origin, ray.origin + ray.direction * 100, Color.red, 2, true);

After

Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);

We should see the actual ray in the scene in a 3d mode:

Note the red line which represents the ray and It could not shoot at the desired position since Camera.main have a different scale.

But if we change the carmera to UICamera to shoot the ray, We could shoot the ray that was desired.

Ray ray = UICamera.currentCamera.ScreenPointToRay(Input.mousePosition);

Hope this could help guys meet with the same pit.