Error in Building an XML File

Hello, I am using PHP to build an XML file, but I keep on getting an XML error when open the file in Google Chrome. --------------------------------------------------------------------------------- This page contains the following errors: error on line 30 at column 318: Entity 'iuml' not defined Below is a rendering of the page up to the first error. -------------------------------------------------------------------------------- is this something to do with document encoding? I am using these as headers for the script header("content-type:text/xml;charset=utf-8"); header("Content-Disposition:attachment;filename=google_feed.xml"); Thanks Joe