CSS Parsed Unambiguously

Success Criteria 4.1.1 requires the web unit be parsed unambiguously. The 
conformance section specifies that all content, including secondary 
resources, must be included for conformance. So it seems that if your CSS 
does not validate then you'll fail SC 4.1.1 (level 1).

Here's an example file that includes an invalid CSS (missing a semicolon).
http://checker.atrc.utoronto.ca/docs/file4.html
http://checker.atrc.utoronto.ca/docs/test1.css

The W3C's validator says regarding the example file: "your CSS style sheet 
needs a correct document parse tree".

I'm just checking with the group on this because invalid CSS is a fairly 
common problem yet doesn't affect accessibility very much.

Do stylesheets need to be valid for level 1 conformance?

Cheers,
Chris