Cannot get rid of this XML error

[shys_aelaes26]

( this is no advertisement, but example )

If you go over to http://ansem.x10.mx/ youll see I have a weird xml error.

XML-verwerking mislukt

XML-verwerking mislukt: syntaxfout (Regel: 1, Karakter: 0)

Document als HTML verwerken
Fout:
missing root element

Specificatie
http://www.w3.org/TR/REC-xml/

In firefox the error is this:
XML-parsefout: geen element gevonden
Locatie: http://ansem.x10.mx/
Regelnummer 1, kolom 1:
^

Which says there is no element found.
I have validated all my xml pages and have added a # in front of several xml related lines in the php to disable it, yet I keep getting this error, not even a failed web page.
I dont understand the error at all.

Can anyone help me with this ( perhaps even with ftp / vnc )

Thanks in advance.

[MaestroFX1]

Could please post your source file ?

Check your source file for unclosed tags.

[descalzo]

Your front page is
1) sending a 500 Internal Server Error header
2) setting the content-type to application/xhtml-xml
3) apparently sending no body.

So the browser is expecting an xml file but it is getting 0 bytes which causes the parsing error.

[shys_aelaes26]

Thanks for point 2 about it being set to xhtml/xml application.
I quoted the lines in index.php with #

The lines were:

// enable xhtml+xml mode if the client supports it
    #if ( stristr(@$_SERVER["HTTP_ACCEPT"],"application/xhtml+xml") )
        #header("Content-type: application/xhtml+xml");
    #else
        header("Content-type: text/html"); 

Thank you very much.
So far it seems to work, there isnt a chance this will cause trouble later on ? just curious about it.