Ragdoll/Raycast/Collider problem.

Hey guys. I'm working on a project where i need a ragdoll with mecanim on my player. I also need a script to check if the player is "grounded" (because player will fall from time to time).

Ragdoll works fine. Mecanim works fine. And here is a script to check if is grounded:

Code (CSharp):

1. void IsGroundedMethod ()
2.     {
3.         if (Physics.Raycast (transform.position + vector2, Vector3.down, 0.5f)) // || Physics.Raycast (transform.position + new Vector3 (0, 0, -0.3f), Vector3.down,0.5f))
4.         {
5.             Debug.DrawRay(transform.position + vector, Vector3.down, Color.red);
6.             isGrounded = true;
7.             anim.SetBool("IsGrounded",true);
8.             anim.SetBool("Fall",false);
9.         }
10.         else {
11.             isGrounded = false;
12.             anim.SetBool("Move",false);
13.             anim.SetBool("IsGrounded",false);
14.             anim.SetBool ("Fall", true);
15.         }
16.     }

Problem mostly is this: script is checking that the player is grounded, but moment later it changes isGrounded to false.

What i have also noticed is that, that sometimes player model's feet sometimes go into the ground, and also colliders don't collide. Here a short video:

any ideas?