GetComponent NullReferenceException

Hey,

When I build my project and try to connect to or start a server the camera of the player flickers. The player camera jumps from looking straight upward to looking straight forward the entire time which causes it to flicker. When I ran the project in the Editor and connect to or start a server it's totally fine expect that if another player is on the server I get a NullReferenceException in this part of my code:

 function OnNetworkInstantiate(){
 
 if(!networkView.isMine){
     var tmp5 = transform.gameObject.GetComponent(MouseLook);//<--Error
     tmp5.enabled = false;
 }
 }

This is not the whole script(It's called PlayerScript) I just filtered out the interesting part. I hope it's enough code.

In the MouseLook script I also have this code:

 void Start(){
   if(!networkView.isMine)
     enabled = false;
 
   if (rigidbody)
     rigidbody.freezeRotation = true;
 }

I also noticed similar problems with GetComponent in other Projects after updating to Unity 4.

I found it weird that these problems started with the Update and I hope someone can help me.

Cheers,

ExTheSea