It says a lot about CSS–based design when you run your first check on a complete draft, and it comes out as valid XHTML, CSS, and hits Section 508 accessibility guidelines without any changes needed. It’s also rather gratifying when only a few slight revisions are needed to get a triple–A from Bobby.
It is, however, a pain in the ass that adding a simple link to an accessibility validator will break your XHTML. I find it excessively picky that “url=myurl&content=” can’t simply be copied and pasted into an href. Instead you must re–format that to “url=myurl&content=”.