ES 3.1 : 'true' as absolute or relative?

[Thomas L. Shinnick]

I was reading some parsing/lexing code when I thought to question how 
named literals were being handled - 'true', 'false', and 'null'.  So 
I went back to the 3.1 spec and then tested with four well-known ES 
implementations, FF3, Opera9, Chrome, and IE7.  If anything, I'm less 
confused but now more worried at the difference between practice and 
(apparent) definition of how to handle these literals.

For reference, some parts of the 3.1 Annex A Grammar:
        Identifier ::                                See 7.6
            IdentifierName but not ReservedWord

        ReservedWord ::                              See 7.5.1
            Keyword
            FutureReservedWord
            NullLiteral
            BooleanLiteral

        BooleanLiteral ::                                See 7.8.2
            true
            false

        PropertyName :                               See 11.1.5
            IdentifierName
            StringLiteral
            NumericLiteral

        PrimaryExpression :                              See 11.1
            ...
            Identifier

        MemberExpression :                               See 11.2
            ...
            MemberExpression . IdentifierName


And some testing with the four current implementations of ES:

      FF      b=new Object(); b.true = false; b.true;    --> 'false'
      Chrome  b=new Object(); b.true = false; b.true;
              SyntaxError: Unexpected token true
      Opera   >>> b=new Object(); b.true = false; b.true;
              Asynchronous script compilation
              Syntax error : line 1 of unknown script :
              Expected identifier
              b=new Object(); b.true = false; b.true;
              ----------------------^
      IE7     b=new Object(); b.true = false; b.true;
              1234567890123456789
              Line:  1
              Char:  19
              Error: Expected identifier

      FF      a = { true: false, false: true }; a.true;  --> 'false'
      Chrome  a = { true: false, false: true }; a.true;
              SyntaxError: Unexpected token true
      Opera   >>> a = { true: false, false: true }; a.true;
              Asynchronous script compilation
              Syntax error : line 1 of unknown script :
              Expected token: '}'
              a = { true: false, false: true }; a.true;
              ----------^
      IE7     a = { true: false, false: true }; a.true;
              Line:  1
              Char:  7
              Error: Expected identifier, string or number

   (for completeness, note similar results are obtained for
              a = { if: false, then: true }; a.if;
     FF is agreeable, the others are not)

      FF      a = { true: false, false: true }; with (a) true;    --> 'true'
              a = { truth: false, lies: true }; with (a) truth;   --> 'false'
          (the others reject keyword 'true' as already shown)

The ES 3.1 draft spec appears to say that 'true' and the others are 
valid 'Identifier's for use in at least the two places tested above, 
PropertyName and MemberExpression.

Testing shows that only FireFox allows this, or at least does in two 
of three tests above.  But given the failure under the 'with' 
construction, I wonder how well it understands the literal 
truth.  (Or is that explained by rule "PrimaryExpression : Identifier" ?)

So....

Was it intended that the named literals 'true', 'false', and 'null' 
(and the keywords) were to be included as valid Identifier's?

How disturbing is it that most of the implementations disagree with 
this definition?

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