animation walk loops with a stop at the end

Hi there, Xcuse my english...

My character walk loop animation is strange, at the end of each loop it is tacking a stop before going ahead again... sort of stand by... it is not a problem of having the same frame at the start and at the end ( the stop is to long for that). and if i play the loop in the animation window it is perfect.

that is the code i wrote to make the caracter go forward :

 if (controller.isGrounded){
 
             moveDirection=Vector3(0,0,Input.GetAxis("Vertical"));
             moveDirection=transform.TransformDirection(moveDirection);
             moveDirection*=speed;

and that is the code to display the walk animation loop:

 if (Input.GetAxis("Vertical") && controller.isGrounded){
                 figurine.animation.CrossFade("walk");
                 }else
                 {
                     figurine.animation.CrossFade("idle");
                 }

so i tried to change CrossFade in to Play but it does not solve the problem...

Any light??

Thank you.