And I've checked the css file. It is in the correct location and since this is template based, the link to the css files is automatically updated depending on where the page is located.
The pages all work great and the styles are importing correctly. It is just the Zeldman's Web Standards Advisor>Web Validation where this error comes up. I am guessing that the W3C is saying that this doesn't fit within the XHTML 1.0 Strict standards?