when i use firefox,i have a error.(IE no problem)
error on line 2 at column 6: XML declaration allowed only at the start of the document

my sites:http://www.rubber-plastic.cn

Seems to be the problem of the codes
<?xml version="1.0" encoding="UTF-8"?>

Right, it's a late reply to this but to all others looking for the same solution refer to this post:

http://www.silverstripe.org/archive/show/1436

I'd also like to add that The problem could also be with your opening <?php declaration as well as possibly your closing ones (which you shouldn't be using in silverstripe.)

I'm using eclipse and this regex found the problem:

\s<\?php

Hope this helps someone.