RSS feed problem

Hi. My Blog is http://www.thegardenhouse.com.br and feed http://www.thegardenhouse.com.br/feed (of corse) 😀 …

But, my feed dont work.

In teh Feed Validator he me show this:

This feed does not validate.

    *      line 3, column 0: Undefined root element: br [help]

          <br />

    *      line 4, column 0: XML parsing error: <unknown>:4:0: junk after document element [help]

          <b>Warning</b>:  Cannot modify header information - headers already sent by  ...

In addition, this feed has issues that may cause problems for some users. We recommend fixing these issues.

    *      Feeds should not be served with the \"text/html\" media type [help]

    *      Your feed appears to be encoded as \"utf-8\", but your server is reporting \"US-ASCII\" [help]

Where it is the problem?

Thx.