Hi, a couple of suggestions:
1. Make sure that <?XML VERSION="1.0"?> is the first line in the code and that there are no spaces before it.
2. Make sure that <?XML VERSION="1.0"?> is the only thing on the first line - that there is a hard return at the end of it
3. Make sure that you don't have any strange hidden characters in the xml (copy it to a simple text editor like vim or textpad, and back again)