sorry if i miss-understood your thread but writing BOM for UTF-8 is at
least unusefull nor might cretaes prob.
because with UTF-8 (not true for UTF-16) the bytes order is imposed by
UTF-8 normative spec.
then it is, at least, not useful.
however if you add the BOM this might confuse parsers (xml or php)
because they want to see a "<" as the first character.