Have you tried to specify encoding in generated XML files? I.e
<?xml version="1.0" encoding="ISO-8859-1"> or
<?xml version="1.0" encoding="UTF-8"> for translated XML file?
No, I haven't. The XML system on the other end is spec'd to only process UTF-8 although I don't know how strict a rule that is. I'll give it a try if santize() doesn't work out.