Loss of encoding on update to XML File

[Anon]

I am recieving "XML error: not well-formed at line xx" errors after updating an xml file.

The problem is being caused by an errant & in the data of the xml document.

The original xml file is UTF-8 encoded and handles the &'s and other illegal characters nicely, but as soon as I update it, the encoding gets lost.

I have tried specifing "UTF-8" with the xml_parser_create, I have tried turning off magic_quotes, to no avail.

Any suggestions ?

ps I am using xml2tree.