Nested classes not implictly in scope of type parameters of their enclosing class

abstract class M[S,T] {
  abstract def m(x:S, y:T):void;
}

abstract class Parent[S,T]{S<:Comparable[S]} {
  abstract def makeM():M[S,T];
}

class Child extends Parent[Child.Bin, Int] {
  static struct Bin implements Comparable[Bin] {
    public def compareTo(y:Bin):Int = 1;
  }
  def makeM() = new M[Bin,Int]() {
    def m(b:Bin, x:Int) {}
  };
}

class Child2 extends Parent[Bin2, Int] {
  static struct Bin2 implements Comparable[Bin2] {
    public def compareTo(y:Bin2):Int = 1;
  }
  def makeM() = new M[Bin2,Int]() {
    def m(b:Bin2, x:Int) {}
  };
}

public class StaticStruct {
  public static def main(Array[String]) { }
}

/home/dgrove/x10-trunk/myTests/StaticStruct.x10:18: Could not find type "Bin2".
/home/dgrove/x10-trunk/myTests/StaticStruct.x10:18: Cannot instantiate type container since type guard was not entailed.    
     	 Type Container: Parent[Bin2, x10.lang.Int]    
     	 Type Guard: [S <: x10.lang.Comparable[S]]
/home/dgrove/x10-trunk/myTests/StaticStruct.x10:18: Type is inconsistent.    
     	 Type: Parent[Bin2, x10.lang.Int]
/home/dgrove/x10-trunk/myTests/StaticStruct.x10:22-24: Method A in container A cannot override method B in container B; attempting to use incompatible return type.    
     	 Method A: makeM(): <anonymous class>{self!=null}    
     	 Container A: Child2    
     	 Method B: makeM(): M[Bin2, x10.lang.Int]    
     	 Container B: Parent[Bin2, x10.lang.Int]    
     	 Expected Type: M[Bin2, x10.lang.Int]    
     	 Found Type: <anonymous class>{self!=null}
4 errors.