Validation failing incorrectly on bad value for encoding name

Hi,

*What I did.*

I installed a copy of the w3c validator on my own server as per the
instructions on http://validator.w3.org/docs/install.html
I installed support for HTML5 and the validator appears to be using the
html 5 validator.
however..

*What went wrong and what i tried
*
When I try to validate a HTML 5 document the validator brings up an error
that:

*Line 4, Column 67*: Bad value text/html; charset=utf-8 for attribute
content on element meta: utf-8 is not a valid character encoding name.

the content in question :

<meta http-equiv="Content-Type" content="text/html; charset=utf-8">*

*
utf-8 is a valid value! Having looked at the w3c guidance (
http://www.w3.org/International/questions/qa-html-encoding-declarations ) I
see that there is a 'shorthand' to declare the character encoding. I tried
this also but still get the same error.

I thought that the error could be something to do with the
validator.nuhtml engine but having Googled it a bit it seems that the
charset is
detected by the w3c validator before sending to the html5 validator.

I have also made sure all the perl dependencies are up to date.