tt_news RSS Feed, show HTMLcode

i work at an RSS-Feed from the tt_news Extension. My Mainproblem is that the XML-File shows the HTML-Structure of my Website, but i don't know why?

Any Ideas?

Thats my Constantscode:

    # RSS2
plugin.tt_news {
  # SYS-Folder mit News
  pid_list               = 61
  # Seite mit Singleanzeige
  singlePid              = 62
  displayXML {
    xmlTitle             = {$c_rss.title}
    xmlLink              = {$baseURL}
    xmlFormat            = rss2
    rss2_tmplFile        = fileadmin/Resources/Private/Templates/rss_2.tmpl
    # Anzahl News in Reader
    xmlLimit             = 10
    xmlDesc              = {$c_rss.description}
    # Sprache
    xmlLang              = {$c_rss.lang}
    title_stdWrap.htmlSpecialChars = 1
    title_stdWrap.htmlSpecialChars.preserveEntities = 1
    subheader_stdWrap.stripHtml = 1
    subheader_stdWrap.htmlSpecialChars = 1
    subheader_stdWrap.htmlSpecialChars.preserveEntities = 1
    subheader_stdWrap.crop = 425 | ...
    subheader_stdWrap.ifEmpty.field = bodytext
    xmlLastBuildDate     = 1
    xmlIcon = main/typo3conf/ext/tt_news/ext_icon.gif
  }
}

And thats the TS-Code:

# RSS
page.headerData.1100 = TEXT
page.headerData.1100.value = <link rel="alternate" type="application/rss+xml" title="RSS-Feed" href="{$baseURL}/rss.xml" />
xmlnews = PAGE
xmlnews {
  typeNum = 100
  10 >
  10 < plugin.tt_news
  10.pid_list >
  10.pid_list = 61
  10.singlePid = 63
  10.defaultCode = XML
  config {
    disableAllHeaderCode = 1
    additionalHeaders = Content-type:text/xml
    no_cache = 1
    xhtml_cleaning = 0
  }
}

TRy with this constans:

### News settings ###
plugin.tt_news {
   displayXML {
    xmlCaching = 1
    xmlLimit = 15
    xmlFormat = rss2
    xmlTitle = News
    xmlLink = http://your.url/
    xmlDesc = description
    xmlLang = de
    title_stdWrap.htmlSpecialChars = 1
    title_stdWrap.htmlSpecialChars.preserveEntities = 1
    subheader_stdWrap.stripHtml = 1
    subheader_stdWrap.htmlSpecialChars = 1
    subheader_stdWrap.htmlSpecialChars.preserveEntities = 1
    subheader_stdWrap.crop = 425 | ... | 1
    subheader_stdWrap.ifEmpty.field = bodytext
    xmlLastBuildDate = 1
    rss2_tmplFile = fileadmin/Resources/Private/Templates/rss_2.tmpl
   }
}