VS 2010 Can’t set WebClient Accept header

I’ve used HTTPWebRequest or WebRequest replete with all the stream readers and such to grab the HTML string of a web page. I was delighted to find the WebClient class which seems to encapsulate most that. I tried to implement it just now but needed to add headers for “UserAgent” and “Accept”. Doing it with HTTPWebRequest worked but not with WebClient. When I look at the headers in the WebClient object after setting them only the UserAgent was apparent and the count of the headers collection was 1. I read the documentation of WebCleint on the MSDN and it said that Accept and other headers are ‘restricted’. I think this means I can’t set Accept to "text/html, application/xhtml+xml, */*". Can someone confirm my understanding and that I can’t use WebClient in this case?

Also it’s my understanding that the default Accept header WebClient uses is “text/HTML”. Does this mean that if the object of my desires has programming on the HTML page it will not work? Which, in this case, it does.