These characters  appear at beginning of XML file

[Anonymous]

you make a header,
header('Content-Type: text/html; charset=iso-8859-1');
and try out putting content

 

[Anonymous]

This problem happens whenever you use unicode content in your page. Guess it happend when you have some unicode text in your page or you are reading it from a file or something
for example when you save a Unicode PHP file with NOTEPAD in Windows, you will see those characters WHILE you cannot see them in Notepad.

Try to open that file using PHPExpert Editor and simply delete those characters from the beginning of your file

ta