This is a BOM, or a Byte Order Mark. http://en.wikipedia.org/wiki/Byte_order_mark
It is the first bytes of a file which can be used to identify the byte order. When encoding the file as ISO-8859-1, the BOM looks like this: .
var diffusedBOM = message.getNode('/');
if (diffusedBOM.indexOf("") == 0) {
diffusedBOM = diffusedBOM.replaceAll("", "");
}
If a string is encoded and then reencoded with a different encoding, the BOM can appear as a different character, like ÿ