More specifically, it seems to happen only when it updates Add/RemoveComponent with string paramter.

For example, in a project I had these 2 lines in a longer js file:

var body : Rigidbody = go.AddComponent ("Rigidbody") as Rigidbody;
springJoint = go.AddComponent ("SpringJoint");

The ScriptUpdater converted them to:

var body : Rigidbody = go.AddComponent.<Rigidbody>()) as Rigidbody;
springJoint = go.AddComponent.<SpringJoint>());

Both lines fail to compile because of extra )