CSS Validator. Re: whitespace: pre-wrap;

Hello,

I noticed in the CSS 2.1 spec (
http://www.w3.org/TR/CSS21/text.html#propdef-white-space) that the
whitespace property allows usage of the 'pre-wrap' value. However, when
validated, it throws an error:

*Errors
URI : http://dev.haugland.ca/style/css/v4.css
Line: 36 Context : pre

Invalid number : white-space pre-wrap is not a white-space value : pre-wrap*

This is moderately concerning because it is documented as an allowed value.
Is this a bug or has it not yet made its way into the validator?

Thanks,
Mike Haugland
http://haugland.ca/