classes cant access superclass fields

I posted this on the mailing lists, but got no reply, so I will create a bug report:

I am having problems with a child class accessing a super
class's fields. Here is the simplest code that demonstrate this
problem:

A.groovy:

class A {
public aa

A() { aa = "this is not set!" }

doit() { println aa }
}

B.groovy:

class B extends A {
B() { //super() /* doesn't matter if this is here or not */ aa = "now B has set it!" doit() }

static void main(args) { bb = new B() }
}

Now when I run:

$ groovy B.groovy

I get:

this is not set.

So it seems that B set his own copy of aa instead of the super
class's aa. If I changed the line:

aa = "now B has set it!"

to:

this.aa = "now B has set it!"

it works.