Not a bug, so moved to Support.
From the the Graphene’s page (http://www.khairul-syahir.com/wordpress-dev/graphene-theme):
Lean and mean codes. I take pride in writing validated XHTML and CSS codes. This theme’s coding follows the standards set by the World Wide Web Consortium (W3C). Note that due to the usage of a few bits of CSS3 in a CSS2.1 stylesheet, validating the CSS will yield a few errors.
All of errors showing are of this sort. They aren’t really errors as much as they are the validator’s saying “I don’t know what this is or how to handle it, so I’m going to call it an error.”
Is there any donate button ?
Go to “Support the developer” toward the bottom of the page I linked above.