Anyway, I was searching around and came across some forum. They claimed the cdata block was:
Still no go. Why not? Did the w3c validator hate me that much? Nope, actually, it’s not lowercase.
Uppercase happens to pass validation perfectly. I don’t know who’s smart idea that was, to make everything else in xml lowercase/case-sensitive, except for cdata, but it was not a good idea. Hope this will help someone out: cdata xhtml blocks are in uppercase!